meh. basically just check everything you would normally check in a car. early model (like first production year) e36’s had problems with their radiator i believe, and others had problems with t-stats and maybe water pumps.
e30’s are very anal about timing belts (MUST be changed every 60k or they snap) but e36’s have timing chains so its a moot point. e36’s also have hydraulic lifters. mmm