SCHEDULE 13G Amendment No. 3 Trimas Corporation Common Stock Cusip # 896215100 Cusip # 896215100 Item 1: Reporting Person - FMR Corp. Item 4: Commonwealth of Massachusetts Item 5: None Item 6: None Item 7: None Item 8: None Item 9: None Item 11: 0.00% Item 12: HC Cusip # 896215100 Item 1: Reporting Person - Edward C. Johnson 3d Item 4: United States of America Item 5: None Item 6: None Item 7: None Item 8: None Item 9: None Item 11: 0.00% Item 12: IN Cusip # 896215100 Item 1: Reporting Person - Abigail P. Johnson Item 4: United States of America Item 5: None Item 6: None Item 7: None Item 8: None Item 9: None Item 11: 0.00% Item 12: IN SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b) Item 1(a). Name of Issuer: Trimas Corporation Item 1(b). Name of Issuer's Principal Executive Offices: 315 East Eisenhower Parkway Ann Arbor, MI 48108 Item 2(a). Name of Person Filing: FMR Corp. Item 2(b). Address or Principal Business Office or, if None, Residence: 82 Devonshire Street, Boston, Massachusetts 02109 Item 2(c). Citizenship: Not applicable Item 2(d). Title of Class of Securities: Common Stock Item 2(e). CUSIP Number: 896215100 Item 3. This statement is filed pursuant to Rule 13d-1(b) or 13d-2(b) and the person filing, FMR Corp., is a parent holding company in accordance with Section 240.13d-1(b)(ii)(G). (Note: See Item 7). Item 4. Ownership (a) Amount Beneficially Owned: None (b) Percent of Class: 0.00% (c) Number of shares as to which such person has: (i) sole power to vote or to direct the vote: None (ii) shared power to vote or to direct the vote: None (iii) sole power to dispose or to direct the disposition of: None (iv) shared power to dispose or to direct the disposition of: None Item 5. Ownership of Five Percent or Less of a Class. If this statement is being filed to report the fact that as of the date hereof, the reporting person has ceased to be the beneficial owner of any of the class of securities, check the following (X). Item 6. Ownership of More than Five Percent on Behalf of Another Person. Not applicable. Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company. Not applicable. Item 8. Identification and Classification of Members of the Group. Not applicable. Item 9. Notice of Dissolution of Group. Not applicable. Item 10. Certification. Inasmuch as the reporting persons are no longer the beneficial owners of any of the number of shares outstanding, the reporting persons have no further reporting obligation under Section 13(d) of the Securities and Exchange Commission thereunder, and the reporting persons have no obligation to amend this Statement if any material change occurs in the facts set forth herein. Signature After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this Schedule 13G in connection with FMR Corp.'s beneficial ownership of the common stock of Trimas Corporation at January 31, 1998 is true, complete and correct. February 10, 1998 Date /s/Eric D. Roiter Signature Eric D. Roiter Duly authorized under Power of Attorney dated December 30, 1997, by and on behalf of FMR Corp. and its direct and indirect subsidiaries