R500 experience

I Bought a year ago the r500 as my first Mercedes Benz. It has been in the shop three times for issues relating to a/c not working correctly to shifting not smooth and causing jerking while driving. We have just moved to a new state and the car cannot be inspected because of a faulty rear break/signal light that is on back order indefinitely from Germany. Mercedes Benz after three call and three hours on the phone has explained that they don't cover alternate transportation while the car is inoperable due to safety issues and they have no idea when the part will be in. Dealer says that they don't cover loaners while the parts are back ordered and I am out of luck till the part comes in which could be months. I am out of my mind about the whole thing. I thought when I purchased a MB they were going to care a little more but I see that's not the case. They in fact care less. I will never again buy a Mercedes Benz after being treaded this way.