Sorry to add a stupid question, but did you replace with new wires? Mine has just recently started to idle just a bit rough (not as bad as it was) and I've heard of the engine starting to run a little rough once its warm if the wires are going or gone. I replaced my wires (but they were from another 560 SEL that LOOKED okay and not neccesarily still good) but plan on getting a New set from Fastlane today.My baby runs at about 80C once she's warm. I had a slight cold idle a while back but the cold start valve I replaced pretty much cured that... my $.02
P.S. What kind/size of tire did you decide to go with anyway?