[cwbiii]

I upgraded to the "BMW performance suspension kit" quite a while ago to the tune of about $1400 plus labor (me and my son). It is a bit harsh of a ride but gives incredible feedback. Its my daily driver to the tune of about 22k miles per year. Its about twice as stiff as the sports suspension option. It rides about an inch+ lower. I brought that back up to about 3/4 of an inch and it is perfect. I seldom rub on anything. I try to avoid all the divet's in the road I can. The biggest problem with my car is rear traction.
I've upgraded to the sport wheels but it still is not enough... I'm going to try a sticky compound set of tires on my next tire change to see how much improvement that will give.

With the 335d I have so much torque that spinning the wheels is just about how hard I push the pedal down... if the electronics don't intervene. Tuning it up higher is a simple and inexpensive ECU reprogramming. A significant increase is advertised... though I should probably make a couple other changes if I plan on using it often. Larger intercooler, radiator and transmission cooling to keep up with the increased heat load.

The diesel reacts to controls slower than gasoline so auto crossing offers some new challenges in operator timing... especially braking into a tight turn and then powering out of it. It doesn't help that this car is a bit heavier than an e46. The ECU reprogramming is supposed to fix some of this sluggishness in the throttle control. When my warranty expires I may try to find out if any of this is going to add to my driving fun. Until then all I'm willing to do is dream and do research. Speaking of which I'm interested in any other 335d/x5d owners with mods and what they think of theirs.