i would not advice u to buy a mercedes 190e 2.3.it has a transmission problem which is a very common problem in it.it may also have a heater problem the fan may not take out the hot air.it also may have fuel inject problem.a minor leak in fuel pipe will allow the fuel to come out at a faster rate
With the Mercedes 190e 2.3L, you can expect to have problems with the fuel injection system. You could also experience hot weather starting problems. Another issue has been slight electrical interferences.
Some of the most common problems with those cars are they burn a lot of oil if not properly maintained. You can buy a Nissan and never put oil in it and it will still go. They have issues with the electrical also if you run into a problem with it not charging.