Interesting thread... with the value of the Z4 (and all similar cars) dropping through the floor recently it looks like I will be keeping this car for the next 3 or 4 years at least. Might have to get a few mods in order to keep things fresh!
Here's my list:
Ditching the run-flats!
Dension ice-link pro (love that!)
De-orange and angel eye lights (not done - need to find someone to do this, I wouldn't have a clue!)
De-orange the side indicators (done.. looks much nicer)
Facelift front (keeping my eyes open)
Stubby aerial (doesnt work that well, but looks the mutt's nut's)
Bin the CDV (still not got around to doing this!)
Tinted windows (not sure, but might be nice)
That's it I think... quad exhausts would be nice, but too much trouble.