Wow, sure glad my 190E has the 5-speed manual! Having your engine rev to 5000rpm from a cold start doesn't sound too smart, but hey - as long as it protects the delicate catty converter (which my '87 thankfully also does not have
The leccy window switches do tend to gam up with dirt because of their horizontal dust-collecting position.
Fortunately, they are easy to DIY-dismantle with a thin flat-blade screwdriver (you can do this within a transparent poly bag to avoid losing the little springs inside, or just take it apart carefully). They are quite simple inside but have a few small fiddly bits, which are fairly obvious to see how they fit together.
Then just clean the internal contacts with a cotton bud and reassemble. It cured my car's non-working windows.