agree with your mechanic 100%!!!! replace the clip now, or you will be forced to replace the regulator assembly later.

the clips are $2-4 a piece from a dealer, (part #51338254781) i think 2 in the front doors (4 total) and 1 in the rear doors (2 total)... do NOT disconnect the airbag, just unscrew it and secure with tape, or rope or something. when you get the window clips, at the same time get the door trim clips too (part #51418224781 or 51418224768, check with dealer), as some of them will break during the repair... they are less than a dollar a piece, i got like 20-30 of them... just in case...