[jmillet]

And you want aftermarket swaybars because???
UUC sells H&R bars that fit the Z4M but hardly worth the trouble; H&R bars are 28mm front and 21mm rear while the OE bars are 27mm front and 22.5mm rear.
The Ground Control Z4M sway bar set is more aggressive if that's what you're looking for.
http://www.ground-control-store.com/.../II=819/CA=231

Originally Posted by Kgolf31

I just got off the phone with Rob at UUC and had an interesting discussion with him.

It appears that the rear bars in their kit, shown below, are guaranteed to fit the Z4Ms because their part number is an exact cross reference to the E46 M3s.

http://www.nexternal.com/shared/Stor...t=products.asp

However, the same doesn't apply to the front bars. He offered to sell me the kit, and take a refund on the bar if it doesn't fit, as he is interested as well if it will.

Anyone have any experience with this? Is this a decent risk to take? Would running a rear-bar only have negative effects if the front bar doesn't fit and I have to find somewhere else to source it from?