I use the Delsing rear camber-arm's as well on our wagon. For some reason, the ends don't look as strong as the Delsing or RennTech camber arms.
(http://www.delsingmotorsport.com)

The Delsing use Aurora Teflon replaceable bushings.

Here's a pic of the Delsing arms:


Guido- unless you're on the track often and/or can afford to replace those 18-inch rears often, I'd keep your rear camber to no more than -2.00 degrees for the street, preferably -1.5 to 1.75
Since you've lowered with H&R springs, you should have some negative camber already.

David- please due tell what you set your front & rear toe to while on the track.

BTW, if you set the rear camber to say -2 or greater (some say -3 to -4 on a twisty track), how are you setting the front camber?

Thanks,
:-) neil
1988 360TE AMG
1993 500E