Look at my car. apart from steering wheel, same thing.
1990 brought the M104 engine.
Things to look for are:
Head gasket - has it been changed, does it leak?
Wirring harness - Has this been changed or is it due?
These are the two major issues I know of.
besides that, these things pretty much apply to most M104 engined vehicles.
If the car is in good shape, and has had both of the above done and is a good price, then You will love the car, as I love mine.
They are beautiful cars, and drive great.
Get it checked out thouroughly.
If it doesn't have service records, you should be very careful.
'92 300CE - Sold
2004 C240 - C7 Wheels
2015 ML350 - P1, Pano, Ash poplar wood, Sport Dinamica interior, Running Boards Keyless go.