Murray Woo

While I am on this forum, besides the limpy headrest, on my 2008 C50, my windshielf wipers flutter across the windshield annoyingly, making squeaking noises, after being used in the rain for a few minutes. They are new, the dealer replaced them, but they couldn't fix the problem. Also there is rattle that comes from going over bumps from the right rear. Apparently there was technical service bulletin out about the rattling and I brought the car to the dealer for it, and they said they fixed and nothing was changed. What the hell. Only 7000 miles on the car too. Oh yeah, and the gas cap that refuses to open and close once in a while ha ha. I am a first time MB driver...are these annoying little problems common to Benz?