Several years ago I installed K-Mac kits on two of my cars. On the one car I installed the full kit (camber + toe bushings), on the other car I installed the camber bushings only. I eventually removed the kits from both cars due to the squeaking noise from the polyurethane bushings; while it wasn't audible from inside the car with the windows up, I would hear it at low speeds with the windows down (i.e., going over speed bumps in a parking lot). I switched to the RDM TEK solution instead for rear camber correction.
However, I did learn that with any rear camber correction kit, you will run out of rear toe adjustment if the car is at all lowered (and even a stock 500E may be borderline, right at the limit of rear toe adjustment). That's why K-Mac included the adjustable toe bushings with their camber kit. I have since sold all the used bushings, but I still have the new, unused toe bushings available. They would be a perfect complement for the RDM TEK kit, or any other type of rear camber correction kit you may have installed. Photos are below.
For price reference - the complete K-Mac kit sells for about $320 (camber + toe) , and the factory rubber eccentric bushings which also allow extra toe adjustment are $354/pair MSRP (toe only, not camber!). These bushings are
half of K-Mac kit #502026 and will work with the following chassis:
124, 129, 170, 201, 202, 203, 208, 209, 210
$150 / obo, free shipping in USA, PayPal ok.