check for rust behind the mouldings that go around the doors and roof. check right behind the rear windows. Also, check to make sure the rear windows roll down with ease, and that the seats only move forward if you press the button on the side (its vacuum operated, if it moves freely there could be a vacuum leak). As far as checking compression, it shouldnt be an issue at 160k. Most importantly, make sure it has been maintained with MB parts, with the right oil, oil filters and services. Another thing, walk around with a magnet to make sure there arent any big bondo areas, and, last but not least, the biggest trouble spots on these cars is the piece of garbage transmission. If it hasnt been rebuilt, it will be soon. Im sure i have more horror stories about my 300cd, so if you have any questions, let me know.
cheers,
justin
82 300cd turbo.
in the middle of a restoration