<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><Version>2.4.0.8</Version><ReportLongName>2117100 - Disclosure - Impairment of Long-Lived Assets</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column FlagID="0"><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><CurrencyCode /><FootnoteIndexer /><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><MCU><KeyName /><CurrencySymbol /><contextRef><ContextID>D2013Q3YTD</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0000053669</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2012-10-01T00:00:00</PeriodStartDate><PeriodEndDate>2013-06-30T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS /><CurrencyCode /><OriginalCurrencyCode /></MCU><CurrencySymbol /><Labels><Label Key="CalendarSupplement" Id="0" Label="9 Months Ended" /><Label Key="Calendar" Id="1" Label="Jun. 30, 2013" /></Labels></Column></Columns><Rows><Row FlagID="0"><Id>1</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>1</Level><ElementName>us-gaap_ImpairmentOrDisposalOfTangibleAssetsDisclosureAbstract</ElementName><ElementPrefix>us-gaap_</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Impairment or Disposal of Tangible Assets Disclosure [Abstract]</Label></Row><Row FlagID="0"><Id>2</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>2</Level><ElementName>us-gaap_AssetImpairmentChargesTextBlock</ElementName><ElementPrefix>us-gaap_</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole>terseLabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="D2013Q3YTD" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;div style="font-family:Times New Roman;font-size:10pt;"&gt;&lt;div style="line-height:120%;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;font-weight:bold;"&gt;Impairment of Long-Lived Assets&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&lt;br clear="none"/&gt;&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-align:justify;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the asset&amp;#8217;s carrying amount may not be recoverable. The Company conducts its long-lived asset impairment analyses in accordance with ASC 360-10-15, &amp;#8220;Impairment or Disposal of Long-Lived Assets.&amp;#8221; ASC 360-10-15 requires the Company to group assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities and evaluate the asset group against the sum of the undiscounted future cash flows. If the undiscounted cash flows do not indicate the carrying amount of the asset group is recoverable, an impairment charge is measured as the amount by which the carrying amount of the asset group exceeds its fair value based on discounted cash flow analysis or appraisals.&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; &lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-align:justify;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&lt;br clear="none"/&gt;&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-align:justify;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;In the first nine months of fiscal 2013, the Company recorded &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;$49 million&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; of asset impairment charges, of which &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;$13 million&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; was recorded in the second quarter and &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;$36 million&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; was recorded in the third quarter, in conjunction with its fiscal 2013 restructuring actions.&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt; The impairment charges related to long-lived assets within all business units, none of which were individually material to the consolidated financial statements. The impairments were recorded within significant restructuring costs on the consolidated statements of income. Refer to Note 8, "Significant Restructuring Costs," of the notes to consolidated financial statements for additional information. The impairments were measured, depending on the asset, either under an income approach utilizing forecasted discounted cash flows or a market approach utilizing an appraisal to determine fair values of the impaired assets. These methods are consistent with the methods the Company employed in prior periods to value other long-lived assets. The inputs utilized in the analyses are classified as Level 3 inputs within the fair value hierarchy as defined in ASC 820,"Fair Value Measurement." The Company concluded it did not have any other significant triggering events requiring assessment of impairment of its long-lived assets at June 30, 2013. &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; &lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-align:justify;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&lt;br clear="none"/&gt;&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-align:justify;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;At March&amp;#160;31, 2012, the Company recorded an impairment charge related to an equity investment. Refer to Note 15, "Fair Value Measurements," of the notes to consolidated financial statements for additional information. The Company concluded it did not have any other significant triggering events requiring assessment of impairment of its long-lived assets at June 30, 2012.  &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; &lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-align:justify;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&lt;br clear="none"/&gt;&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-align:justify;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;Goodwill reflects the cost of an acquisition in excess of the fair values assigned to identifiable net assets acquired. The Company reviews goodwill for impairment during the fourth fiscal quarter or more frequently if events or changes in circumstances indicate the asset might be impaired. The Company performs impairment reviews for its reporting units, which have been determined to be the Company&amp;#8217;s reportable segments or one level below the reportable segments in certain instances, using a fair-value method based on management&amp;#8217;s judgments and assumptions or third party valuations. The fair value of a reporting unit refers to the price that would be received to sell the unit as a whole in an orderly transaction between market participants at the measurement date. In estimating the fair value, the Company uses multiples of earnings based on the average of historical, published multiples of earnings of comparable entities with similar operations and economic characteristics. In certain instances, the Company uses discounted cash flow analyses to further support the fair value estimates. The inputs utilized in the analyses are classified as Level 3 inputs within the fair value hierarchy as defined in ASC 820. The estimated fair value is then compared with the carrying amount of the reporting unit, including recorded goodwill. The Company is subject to financial statement risk to the extent that the carrying amount exceeds the estimated fair value. The impairment testing performed by the Company in the fourth quarter of fiscal year 2012 indicated that the estimated fair value of each reporting unit substantially exceeded its corresponding carrying amount including recorded goodwill, and as such, no impairment existed at September&amp;#160;30, 2012. No reporting unit was determined to be at risk of failing step one of the goodwill impairment test.&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; &lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-align:justify;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&lt;br clear="none"/&gt;&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-align:justify;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;At October&amp;#160;1, 2012, the Company assessed goodwill for impairment in the Automotive Experience business due to the change in reportable segments as described in Note 17, &amp;#8220;Segment Information,&amp;#8221; of the notes to consolidated financial statements. As a result, the Company performed impairment testing for goodwill under the new segment structure and determined that the estimated fair value of each reporting unit substantially exceeded its corresponding carrying amount including recorded goodwill, and as such, no impairment existed at October&amp;#160;1, 2012. No reporting unit was determined to be at risk of failing step one of the goodwill impairment test.&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; &lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-align:justify;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&lt;br clear="none"/&gt;&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-align:justify;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;While the estimated fair value of each reporting unit substantially exceeded its corresponding carrying amount including recorded goodwill at the assessment dates indicated above, a prolonged significant decline in the European automotive industry could put the Company at risk of not achieving future growth assumptions and could result in impairment of goodwill or other long-lived assets, or result in additional restructuring actions, within the Automotive Experience business, which could be material to the consolidated financial statements.&lt;/font&gt;&lt;/div&gt;&lt;/div&gt;</NonNumbericText><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>nonnum:textBlockItemType</ElementDataType><SimpleDataType>na</SimpleDataType><ElementDefenition>The entire disclosure for the details of the charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value. 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