Actually im not 100% sure that the cluster from a z3 will fit, hopefully someone else can confirm about z3 cluster fitment, although I think they do. However you will at least need a cluster from a 6 cyl. The reason being is that you're going from a 4cyl to a 6 cyl, the tach doesn't read correctly.
Wiring harness shouldnt be a big deal if its not included in the sale, you can find them on BFC for like $100, just easier if its already attached to the engine.
The DME is the computer that controls the engine, and thats actually what needs to be reprogrammed by BMW. The DME controls EWS which is an anti theft system. Basically your car wont start unless the key the DME is programmed for is what starts the car. Since you wont be using the z3 keys, you will have to get the car towed to BMW to have the EWS realigned. You could also opt to send the DME off to a tuner who can remove EWS and skip that step with BMW, but also lose the security feature. __________________ 
-Alex |