If you have a chance to check it out yourself, make sure everything works including:

- central locking from all points
- remote locking from all points including windows up and sunroof close
- closing assist at all points
- parking aid antennas
- retracting trunk handle
- all functions of power seat adjustment
- all functions of power mirror adjustment (inlcuing rear view mirror) and side mirror retract
- both functions of steering wheel adjustment
- rear headrest collapse
- all functions of ACC or as much as you can check
- all functions of power windows and sunroof including express
- all functions of stereo and CD changer if equipped

Not all of these things are difficult and/or expensive to repair.

And general condition items like:

- complete tool kit
- complete first aid kit
- pillar trim in place. My 140 has pillar upholstery lifting in a couple of places.

Of course there's checking history and records along with the mechanical aspects of the car, but that's not much different from checking the basic soundness of a 126 or 124.

Spend an evening at JimF's website and familiarize yourself with the nuances of the 140. Things like engine temps of 110C in traffic being normal were a shock to me and might have meant passing on an otherwise good car.

I don't know if JimF's website goes into the SRS light but apparently a lot of owners, including me, live with an SRS light that stays on for a minute or so after every start. Don't get in a frontal collision until it goes out

Sixto
95 S420
91 300SE
87 300SDL
83 300SD