So I have 2 x S4's of 1988 vintage. Car1. Next to the Headlight Beam Regulator knob there is a black "golf tee" that can be pulled up and pushes down again. Car2. Next to the Headlight Beam Regulator knob there is a black rocker switch. I cannot see anything relatable in the Driver"s Manual.Factory option or aftermarket ? Stealth turbo switches ? Regards, Beau