arches are completely different from old and late models. tailights and bumpers are different as well. but like richie said its mostly interior parts and body parts like hood, fenders, sunroof, trunk, mirrors.. things of that sort you should be able to swap.
1990 325i Sterling Silver Metallic/Black leather.
M52B28 OBD-I W/ S52 Cams, M50 Manifold, SS Headers, Short ram intake, Stage 2 clutch w/ 14lb flywheel, Mark D chip tune.
Bilstein Sports with Eibach Pro springs + E90 drop hats, F+R Strut bars, '04 330ci Steering rack (3.0 Lock to lock, 13:1)
Custom Built BBS RS's 16x8 square.