Common issues on the E43 are, Rear springs like to go on them, unless you get some uprated one's. also the alternator packs on them very often. The SMG and SMG II. I think the SMG has a clutch and the SMG II have a torque convertor. Cant remember which ones it is, but one is not good when doing a launch control.
Also i'm thinking of getting one too or an edition 30. I spoke to a BMW M3 owner, he said i've had both SMG and manual. SMG are sh!te, them were his words. he says kid if you want one, go for a Manual. you can play about with them alot better. also SMG pumps ate common to go too.
Also the E46 has big bills when coming for maintenance. after so many thousand miles, they need to go in and get all the valves checked and adjusted. a mate has bought one and it costed him near enough £900.00 to have that sorted.
Also the rear tyres need to have the same amount of thread, if one has 4mm and the other has 6mm it will handle like sh!t.
The E36 is good, but you get the sequential gearbox in these too, but they are sh!te. basically their an SMG box.
Do your research and take it on from there. These cars are cheap to buy, but maintenance kills you
