X0306 4 2017-04-06 1 0001616817 Metaldyne Performance Group Inc. MPG 0001626084 ASP MD Investco LP C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK NY 10171 0 0 1 0 0001504662 American Securities Partners VI, L.P. C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK NY 10171 0 0 1 0 0001504663 American Securities Partners VI(B), L.P. C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK NY 10171 0 0 1 0 0001532680 American Securities Partners VI(C), L.P. C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK NY 10171 0 0 1 0 0001532681 American Securities Partners VI(D), L.P. C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK NY 10171 0 0 1 0 0001627455 American Securities Associates VI, LLC C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK NY 10171 0 0 1 0 0001475483 AMERICAN SECURITIES LLC C/O AMERICAN SECURITIES LLC 299 PARK AVE, 34TH FLOOR NEW YORK NY 10171 0 0 1 0 0001626076 Penn Kevin S. C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK NY 10171 1 0 0 0 0001626074 Easton Loren S. C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK NY 10171 1 0 0 0 0001626077 Fisch Michael G. C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK NY 10171 1 0 0 0 Common Stock, par value $0.001 per share ("Common Stock") 2017-04-06 4 D 0 51368003 D 0 D Common Stock 2017-04-06 4 D 0 5290 D 0 D Common Stock 2017-04-06 4 D 0 3135 D 0 D Common Stock 2017-04-06 4 D 0 3135 D 0 D Common Stock 2017-04-06 4 D 0 3135 D 0 D Reflects disposition in connection with the consummation of the transactions contemplated by the Agreement and Plan of Merger, dated as of November 3, 2016 (the "Merger Agreement"), by and among the Issuer, American Axle & Manufacturing Holdings, Inc. ("AAM") and Alpha SPV I, Inc., a wholly-owned subsidiary of AAM ("Merger Sub"), pursuant to which Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly-owned subsidiary of AAM and each share of Common Stock was exchanged for $13.50 in cash (the "Cash Consideration") and 0.5 of a share of common stock of AAM (the "Share Consideration" and, together with the Cash Consideration, the "Merger Consideration"). The closing price of a share of Common Stock on April 5, 2017 (the last trading day prior to the effectiveness of the Merger) was $21.90, and the closing price of a share of AAM common stock on April 6, 2017 (the effective date of the Merger) was $17.00. Each Reporting Person disclaims beneficial ownership of the reported securities except to the extent of such Reporting Person's pecuniary interest therein, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose. Represents (A) 51,365,358 shares directly owned by ASP MD Investco LP ("Investco") that may also be deemed to be indirectly beneficially owned by: (i) American Securities Partners VI, L.P., American Securities Partners VI(B), L.P., American Securities Partners VI(C), L.P. and American Securities Partners VI(D), L.P. (each, a "Sponsor"), the owners of partnership interests in Investco; and (ii) American Securities Associates VI, LLC, the general partner of each Sponsor. American Securities LLC ("ASL") provides investment advisory services to each Sponsor, and (B) 2,645 shares of common stock granted to Kevin Penn, Loren Easton and Michael Fisch in their capacity as directors of the Issuer; pursuant to an arrangement between each of Mr. Penn, Mr. Easton, and Mr. Fisch and ASL, such shares of common stock were assigned to and held for the benefit of ASL. Reflects disposition of shares of restricted stock under the Merger Agreement, pursuant to which each share of restricted stock of the Issuer was canceled in exchange for the Merger Consideration; such shares had been granted to Kevin Penn, Loren Easton and Michael Fisch in their capacity as directors of the Issuer and were assigned to and held for the benefit of ASL pursuant to an arrangement between each of Mr. Penn, Mr. Easton, and Mr. Fisch and ASL. Reflects disposition under the Merger Agreement, pursuant to which each restricted stock unit of the Issuer became fully vested immediately prior to the Merger and was canceled in exchange for the Merger Consideration; such shares had been granted to Kevin Penn, Loren Easton and Michael Fisch in their capacity as directors of the Issuer and were assigned to and held for the benefit of ASL pursuant to an arrangement between each of Mr. Penn, Mr. Easton, and Mr. Fisch and ASL. Kevin Penn is a managing director of ASL (and was a director of Issuer). Pursuant to an arrangement between Mr. Penn and ASL, all director fees received by him from the Issuer were paid over to or held for the benefit of ASL. Loren Easton is a managing director of ASL (and was a director of Issuer). Pursuant to an arrangement between Mr. Easton and ASL, all director fees received by him from the Issuer were paid over to or held for the benefit of ASL. Michael G. Fisch is President and Chief Executive Officer of ASL (and was a director of Issuer). Pursuant to an arrangement between Mr. Fisch and ASL, all director fees received by him from the Issuer were paid over to or held for the benefit of ASL. Exhibit 99.1 Joint Filer Information, incorporated herein by reference ASP MD Investco LP, By: ASP Manager Corp., its general partner, /s/ Michael G. Fisch, as President 2017-04-10 American Securities Partners VI, L.P., By: American Securities Associates VI, LLC, its general partner, /s/ Michael G. Fisch, as Managing Member 2017-04-10 American Securities Partners VI(B), L.P., By: American Securities Associates VI, LLC, its general partner, /s/ Michael G. Fisch, as Managing Member 2017-04-10 American Securities Partners VI(C), L.P., By: American Securities Associates VI, LLC, its general partner, /s/ Michael G. Fisch, as Managing Member 2017-04-10 American Securities Partners VI(D), L.P., By: American Securities Associates VI, LLC, its general partner, /s/ Michael G. Fisch, as Managing Member 2017-04-10 American Securities Associates VI, LLC, /s/ Michael G. Fisch, as Managing Member 2017-04-10 American Securities LLC, /s/ Michael G. Fisch, as President and Chief Executive Officer 2017-04-10 /s/ Kevin S. Penn 2017-04-10 /s/ Loren S. Easton 2017-04-10 /s/ Michael G. Fisch 2017-04-10