Rear end
2 Answers
Lift up the rear end (both tires off the ground) with the car in neutral, turn one tire by hand. If they turn the same way, it's POSI, if they turn opposite, then it''s not.
It would have an open dif (sending power to one wheel), not a limited slip dif (LSD), unless it came with ASC (automatic stability control) there would be an ASC button on the center console http://www.bmwmregistry.com/faq/E36_M3_Auto_Shifter.jpg