Z3 is a hybrid e30/e36 with some unique parts thrown in.
- Interior quality is pretty poor with sagging glove box, seat slider problems and overall cheap feel.
- be prepared for lots of wind/drivetrain/road noise
- rear suspension is semi trailing arm like the e30, it can be fun with proper sport shocks/springs but it's a little primitive.
- engine options are wide open, every e36 and e46 engine can be had.
- work access under the hood is awesome
Z4's really are an enormous leap forward in every way but the price reflects that.