Quote Originally Posted by thesameguy View Post
Early traction control was just brakes, so any car with ABS could potentially have TCS. There was a company in... somewhere that made a module to plug into Bosch and ATE ABS systems to retrofit TCS. It was kinda cool.

Electronic throttle actuators were the game changer that made actual stability control possible. TCS is really limited to wheel spin, ESP et al is what helps with car spin.
The E36es had a second TB that the computer controlled.