I'm deciding between these cars. I want navigation/entertainment system and some of the other stuff and with all that the BMW comes out about 3,000 cheaper and either one of these cars is already quite a lot of money for me so price definitely does matter. Right now, I'm going with the BMW (because of price but also sporty looks) but the Mercedes definitely pleases me too with looks and capabilities. Which would be better for the money and what are some of the main differences? For the MB, I would add on the multimedia package and quickdrive and for the BMW, the navigation system, power front seats, BMW assist, and the quickdrive equivalent.

If you want more room and a more practical car, get the Mercedes.
If you want a car that is more fun to drive and looks sportier, go for the BMW.