I just added a PAD switch to my 500E. I am sure they are on the same lines. We took out the rear light and put the switch in that slot. The switch comes with a ugly looking switch (maybe Renntech will be different) so I took a defeat switch from a late model S-class instead.

From what I can tell the ASR switch activates the "snowchains" bypass (the snowchain light is always on) of the ASR circuit, so that instead of there allowing wheel spin up to 10mph (or whatever the speed is), it allows wheelspin throughout the speed range. There is definitely wires that are cut in the process, and another thing, it completely wipes out all the fault codes in the computer.

As far as wheelspin, there is a lot (even with 275/40 Pilot Sports), but she hooks up strong and just takes off! I have not had chance to check with the g-tech, but she feels faster.

Be careful of hitting the rev. limiter on slippery roads, as one wheel will really spin.

David Hendy
'92 500E 66k miles