This article supersedes TSB 21-2220 to update the model years affected and part list. Some 2018-2024 Mustang coupe vehicles may exhibit a sagging headliner or gap where the headliner meets the upper door weatherstrip. This may be due to an outward bent door frame moulding not allowing the weatherstrip to overlap the headliner properly. To correct this condition, follow the Service Procedure to replace the door frame moulding.
