Dorman Products, Inc.

Director and Executive Officer Trading Arrangements

Entry into Rule 10b5-1 Trading Plans. The following table describes contracts, instructions, or written plans for the purchase or sale of the Company’s common stock intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) (each, a “Rule 10b5-1 Plan”) entered into during the quarter ended September 27, 2025, by our directors and officers (as defined under Rule 16b-1(f) of the Exchange Act).

1 Each Rule 10b5-1 expires upon the date shown or, if earlier, upon completion of all authorized transactions under such Plan.

2 Plan includes (i) the sale of $300,000 of common stock on certain prescribed dates, with the exact number of shares to be sold pursuant to the plan to be based upon the prior day’s closing price (with the total dollar proceeds received from such order potentially being higher or lower than expected if the market price rises above or below the price used to calculate the number of shares to be sold), (ii) the sale of up to 1,500 shares of the Company’s common stock currently held by Ms. Long, and (iii) the potential exercise of vested stock options and the associated sale of up to 5,453 shares of the Company’s common stock. The actual number of shares sold may be less based on tax withholdings.

3 Plan includes the sale of up to 31,000 shares of the Company’s common stock currently held by Mr. Olsen.

4 Plan covers (i) 70,000 shares of the Company’s common stock owned directly by Mr. Berman, and (ii) 125,501 shares of the Company’s common stock owned (a) by certain family trusts for which Mr. Berman serves as co-trustee, and (b) by certain family trusts for the benefit of Mr. Berman’s children.

5 Plan includes the sale of up to 7,000 shares of the Company’s common stock currently held by Mr. Braun.

6 Plan includes the sale of up to 5,953 shares of the Company’s common stock currently held by Mr. Leff.

Termination of Rule 10b5-1 Trading Plans. On August 20, 2025, Donna Long, the Company’s SVP, Chief Information Officer, terminated a 10b5-1 Plan dated June 9, 2025 (the “June 2025 Long 10b5-1 Plan”). The June 2025 Long 10b5-1 Plan provided for (i) the sale of $300,000 of common stock on certain prescribed dates, with the exact number of shares to be sold pursuant to the plan to be based upon the prior day’s closing price (with the total dollar proceeds received from such order potentially being higher or lower than expected if the market price rises above or below the price used to calculate the number of shares to be sold), (ii) the sale of up to 1,500 shares of the Company’s common stock, and (iii) the potential exercise of vested stock options and the associated sale of up to 5,299 shares of the Company’s common stock. As of the date of termination, no shares of common stock had been sold pursuant to the terms of the June 2025 Long 10b5-1 Plan.

No other director or officer terminated a Rule 10b5-1 Plan during the quarter ended September 27, 2025.

Non-Rule 10b5-1 Trading Plans. There wereno non-Rule 10b5-1 trading arrangements entered into or terminated by our directors and officers during the quarter ended September 27, 2025.