Description of the Business	9 Months Ended
Sep. 30, 2025
Accounting Policies [Abstract]
Description of the Business	NOTE 1 – DESCRIPTION OF THE BUSINESS Description of the Business The principal business of Superior Industries International, Inc. (referred herein as the “Company” or “Superior”) is the design and manufacture of aluminum wheels for sale to original equipment manufacturers (“OEMs”) in North America and Europe, and to the aftermarket in Europe. The Company’s aluminum wheels are primarily sold to OEMs for factory installation on new light vehicles. Aluminum wheels sold in the European aftermarket are under the brands ATS, RIAL, ALUTEC, and ANZIO. North America and Europe represent the primary markets for the Company’s products, but it has a diversified global customer base consisting of North American, European, and Asian OEMs. Merger On December 8, 2025 (the “Closing Date”), the Company, SUP Parent Holdings, LLC, a Delaware limited liability company (“Parent”), and SUP Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Parent (“Merger Sub”) completed the previously announced Merger, contemplated by that certain Agreement and Plan of Merger, dated as of July 8, 2025 (the “Merger Agreement”). At the effective time of the Merger on the Closing Date (the “Effective Time”), in accordance with the Merger Agreement, Merger Sub merged with and into the Company (the “Merger”), with the Company surviving the Merger as a direct wholly owned subsidiary of Parent. Immediately prior to the Effective Time, Parent held Common Shares that represented approximately 17.6% of the total voting power of the Company. At the Effective Time, in accordance with the terms and conditions set forth in the Merger Agreement, each Common Share and each share of preferred stock, par value $0.01 per share designated as Series A Preferred Shares (the “Series A Preferred Shares” and, together with the Common Shares, the “Shares”), in each case, issued and outstanding immediately prior to the Effective Time (other than Shares owned by (i) Parent or Merger Sub or any of their respective Subsidiaries, (ii) the Company as treasury stock and (iii) holders of Common Shares who have not voted in favor of the Merger or consented thereto and have properly exercised and perfected and not withdrawn, waived or lost a demand for appraisal rights pursuant to Section 262 of the Delaware General Corporation Law) was converted into the right to receive: • with respect to each Common Share, $0.09 per Common Share in cash, without interest thereon; and • with respect to each Series A Preferred Share, (1) $39.49 per Series A Preferred Share in cash and (2) 0.23 units of limited liability company interests of Parent per Series A Preferred Share. At the Effective Time, in accordance with the Merger Agreement: • each outstanding time-based restricted stock unit (a “Company Restricted Stock Unit”) that was granted under the Company’s 2018 Equity Incentive Plan (the “Company Stock Plan”) that was outstanding as of immediately prior to the Effective Time, whether vested or unvested, became fully vested and terminated and automatically cancelled as of immediately prior to the Effective Time in exchange for the right to receive a lump sum cash payment of an amount equal to $0.09 per Company Restricted Stock Unit; and • each outstanding performance-based restricted stock unit (a “Company Performance Stock Unit”) that was granted under the Company Stock Plan that was outstanding as of immediately prior to the Effective Time, whether vested or unvested, became fully vested as if the applicable level of performance was achieved at target and terminated and automatically cancelled as of immediately prior to the Effective Time in exchange for the right to receive a lump sum cash payment of an amount equal to $0.09 per Company Performance Stock Unit. The Company used the proceeds of borrowings under the Third Amendment (as defined in Note 8 “Debt and Other Financing Arrangements”) to pay the cash consideration in the Merger. Additional information about the Merger is set forth in the Company’s Current Report on Form 8-K filed with the SEC on December 8, 2025.

Description of the Business

The principal business of Superior Industries International, Inc. (referred herein as the “Company” or “Superior”) is the design and manufacture of aluminum wheels for sale to original equipment manufacturers (“OEMs”) in North America and Europe, and to the aftermarket in Europe. The Company’s aluminum wheels are primarily sold to OEMs for factory installation on new light vehicles. Aluminum wheels sold in the European aftermarket are under the brands ATS, RIAL, ALUTEC, and ANZIO. North America and Europe represent the primary markets for the Company’s products, but it has a diversified global customer base consisting of North American, European, and Asian OEMs.

Merger

On December 8, 2025 (the “Closing Date”), the Company, SUP Parent Holdings, LLC, a Delaware limited liability company (“Parent”), and SUP Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Parent (“Merger Sub”) completed the previously announced Merger, contemplated by that certain Agreement and Plan of Merger, dated as of July 8, 2025 (the “Merger Agreement”). At the effective time of the Merger on the Closing Date (the “Effective Time”), in accordance with the Merger Agreement, Merger Sub merged with and into the Company (the “Merger”), with the Company surviving the Merger as a direct wholly owned subsidiary of Parent. Immediately prior to the Effective Time, Parent held Common Shares that represented approximately 17.6% of the total voting power of the Company.

At the Effective Time, in accordance with the terms and conditions set forth in the Merger Agreement, each Common Share and each share of preferred stock, par value $0.01 per share designated as Series A Preferred Shares (the “Series A Preferred Shares” and, together with the Common Shares, the “Shares”), in each case, issued and outstanding immediately prior to the Effective Time (other than Shares owned by (i) Parent or Merger Sub or any of their respective Subsidiaries, (ii) the Company as treasury stock and (iii) holders of Common Shares who have not voted in favor of the Merger or consented thereto and have properly exercised and perfected and not withdrawn, waived or lost a demand for appraisal rights pursuant to Section 262 of the Delaware General Corporation Law) was converted into the right to receive:

•

with respect to each Common Share, $0.09 per Common Share in cash, without interest thereon; and

•

with respect to each Series A Preferred Share, (1) $39.49 per Series A Preferred Share in cash and (2) 0.23 units of limited liability company interests of Parent per Series A Preferred Share.

At the Effective Time, in accordance with the Merger Agreement:

•

each outstanding time-based restricted stock unit (a “Company Restricted Stock Unit”) that was granted under the Company’s 2018 Equity Incentive Plan (the “Company Stock Plan”) that was outstanding as of immediately prior to the Effective Time, whether vested or unvested, became fully vested and terminated and automatically cancelled as of immediately prior to the Effective Time in exchange for the right to receive a lump sum cash payment of an amount equal to $0.09 per Company Restricted Stock Unit; and

•

each outstanding performance-based restricted stock unit (a “Company Performance Stock Unit”) that was granted under the Company Stock Plan that was outstanding as of immediately prior to the Effective Time, whether vested or unvested, became fully vested as if the applicable level of performance was achieved at target and terminated and automatically cancelled as of immediately prior to the Effective Time in exchange for the right to receive a lump sum cash payment of an amount equal to $0.09 per Company Performance Stock Unit.

The Company used the proceeds of borrowings under the Third Amendment (as defined in Note 8 “Debt and Other Financing Arrangements”) to pay the cash consideration in the Merger.

Additional information about the Merger is set forth in the Company’s Current Report on Form 8-K filed with the SEC on December 8, 2025.