Generally upgrading to the M coupe/roadster rear subframe is the upgrade. If you are welding on the tub, you might as well gut it and weld in a cage. Generally the 1.8/1.9 powered ti does not suffer suspension mount tears unless the car was tracked- even then it’s pretty rare. The Z3 2.8/3.0 parts fit but the track is wider. That limits tire choices unless you go “wide body” which I suppose is an option too. |