Some early e88s had rubbing issues, i believe it was on the sides a few inches behind the windows, defective examples would eventually wear thru the vert cloth. FWIW my e88 is an early n54 and the top is fine, save for a bit of creasing, but thats to be expected with time. Dont quote me on this but i *believe* there was a tsb for the rubbing issue.
E88 N54 Alpinweiss/Coral Red/Motiv HTA 3586r Tial .82AR/Other stuff...652WHP
F30 N55 XDrive EBII