Check oil leak around upper front cover.

Check reverse. If the car doesn't go into reverse as soon as you drop it in, you will be needing a tranny replacement soon. I didn't pay attention when I bought mine, after the fluid got good and hot, reverse would not pull. I was told by a Master Mercedes Tech this was a common problem.

Also make sure you don't have problems with the A/C vents switching. Punch your defrost and vent buttons to make sure they switch back and forth without problems.