1) 1st mod - Driver: get used to the car, its a lot faster than your Z4. learn to handle the car properly. take an advanced driving class.Originally Posted by flazisismus
2) get a nice sticky set of tires and some wider rims. 16x7.5 at least.
3) after that do what you'd like. Springs/Sway bar for suspension, or a Cobb AP to flash to Stage 1 and smooth out the power band, then get exhaust stuff to get more power.
Check out the Sticky and FAQ at the top of the forum.
Synthetic isnt necessary, but do it if you'd like.
RE92's suck at everything they do. I use them in the winter here in New England but that is it.