They have a little 4x4 approx. piece that looks like a radar detector. It suction cups to the windshield like a radar detector also. It has a digital readout and it tells you your 0 to 60 time, quarter mile elapses time and G force as well as horsepower to the rear wheels. Does anybody have one and are they worth $100+. Does anybody know someone that has one and what do they think of it??? Ron |