Tail Light problems of the 2001 Mercedes Benz SLK230

I have less than 50k miles and had to replace the mass air flow sensor twice and now check engine light is on again for the same service needed. I have paid out of pocket not to mention the inconvenience of having it in the shop so many times also have had to replace transmission sensors and tail light, which mercedes did not reimburse for original charge, just re- replaced. Now problems happening with rear mirror. This is ridiculous mercedes should stand by there product that is supposed to last forever and I have had nothing but problems.