<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-11-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001327318</issuerCik>
        <issuerName>TrueCar, Inc.</issuerName>
        <issuerTradingSymbol>TRUE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001021249</rptOwnerCik>
            <rptOwnerName>UNITED SERVICES AUTOMOBILE ASSOCIATION</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>9800 FREDERICKSBURG RD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN ANTONIO</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78288</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001607293</rptOwnerCik>
            <rptOwnerName>USAA Property Holdings, Inc.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>9800 FREDERICKSBURG ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN ANTONIO</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78288</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-11-02</value>
                <footnoteId id="F1"/>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>21605</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.053</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12010741</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-11-03</value>
                <footnoteId id="F1"/>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>178395</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.2012</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11832346</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1633347</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>USAA Property Holdings, Inc.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The transactions reported on this form were executed pursuant to a 10b5-1 plan adopted as of August 26, 2015.</footnote>
        <footnote id="F2">Execution Breakdown of Price/Sold Shares:

PRICE     SOLD SHARES

$6.00       7,800
$6.002        100
$6.005        200
$6.01       2,300
$6.015        200
$6.02         100
$6.03         100
$6.0325       100
$6.04       1,300
$6.05         200
$6.06       1,000
$6.065        500
$6.07         828
$6.08       1,332
$6.09         500
$6.095        100
$6.10         400
$6.13         600
$6.135        300
$6.14         800
$6.145        100
$6.15         945
$6.17       1,000
$6.1715       300
$6.173        200
$6.175        300</footnote>
        <footnote id="F3">Execution Breakdown of Price/Sold Shares: (continuation will be included in footnote #4)

PRICE     SOLD SHARES

$6.00     3,195
$6.01     4,052
$6.02     2,631
$6.03     3,800
$6.035      300
$6.04     5,898
$6.045      100
$6.05     8,774
$6.055      100
$6.06     5,100
$6.065    1,000
$6.07     6,008
$6.075    1,000
$6.08     5,976
$6.085      400
$6.0875     100
$6.09     4,100
$6.095      200
$6.10     7,226
$6.105      200
$6.11     1,832
$6.115      700
$6.12     2,400
$6.125      100
$6.13     5,100
$6.135      400
$6.1375     100
$6.14     4,800
$6.145      200
$6.15     4,075
$6.155      300
$6.16     1,900
$6.165      200
$6.17     2,100
$6.175      800
$6.19     2,070
$46.195   1,000
$6.1975     100
$6.20     3,693
$6.205      100
$6.21     1,034
$6.215      300
$6.22     4,834
$6.225      500
$6.23     6,000
$6.24     3,260
$6.245      200</footnote>
        <footnote id="F4">Execution Breakdown of Price/Sold Shares: (continuation from footnote #3)

PRICE     SOLD SHARES

$6.25     1,140
$6.26       100
$6.27     2,300
$6.28     1,800
$6.29       200
$6.295      400
$6.30     3,300
$6.305    1,500
$6.31     4,350
$6.315    2,482
$6.32     8,100
$6.325    1,200
$6.33     2,953
$6.335      300
$6.34    11,549
$6.345      300
$6.35     5,600
$6.355    1,324
$6.36     3,795
$6.365      500
$6.37     5,600
$6.38       990
$6.39     3,000
$6.395    1,200
$6.40     1,100
$6.41     1,400
$6.42     1,754
$6.425      100
$6.43       700
$6.44     1,100</footnote>
        <footnote id="F5">USAA Property Holdings, Inc. is a wholly owned subsidiary of United Services Automobile Association.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Douglas I. Ward, Vice President and Chief Investment Officer</signatureName>
        <signatureDate>2015-11-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
