I am getting ready to buy a new vehicle next month. I have done all of the research I can on these three models, and it is still up in the air. I have almost narrowed it down to the Merc and the BMW, but I still like the Audi as well. The main questions I still have pertain to the maintenance costs and the resale value. Which is the better choice pertaining to these issues. Also, opinions on overall best choice would be appreciated. I am shooting more for luxury rather than sporty.