sticking wiper blade
I could be wrong, but suggest that you look into the condition of your car's battery. Is it charging up properly and holding the power supply long enough for you to restart the engine or use other electrical stuff after a week of rest in the garage? Have the battery checked and changed if this is the culprit. Happenned to me about 4 months ago when my sunroof moved very sluggishly while opening and closing, wouldn't tilt and the cd player and cassette player sounded a bit slow. Changed to a new Benz type battery with the gas escape outlet tube and everything's alright now. Even the single blade wiper is going like a fan when I select the high speed level. If I'm wrong, sorry. Just came across your thread and had to say something, adios.
1994 C180 (Lots of problems, but curing them one by one. Hope to finish them all by Christmas 2002!)