Don't know if this helps - but Hey!! I have noticed in pictures of Mercedes for sale on Ebay that there is no Hood insulation on cars in Florida. My insulation is foam and 1" thick - could this be holding the extra heat in?? All those in Texas and elsewhere who are getting normal 85C-90C temps - do you have insulation pad under hood? Those whose temps are like mine - do you have insulation pad?? Maybeeeee????

My 1988 300SEL is an original Florida car and it has the underhood insulation. I know mine is an I6, but the highest I have ever seen the temp was slightly above 80°C. It will go there when the engine first warms up, then it falls back down to 80°C.