The GPS unit used to test the blue Camaro was the VBOX Pro Lite. This small unit can be connected directly to a laptop for analysis in real time, and accurately gives acceleration figures, braking distances, and lap times. According to VBOX's Web site, its GPS units, when compared back-to-back with optical testing equipment, gives very accurate data. Maybe this is why its customer list contains almost every single auto and tire manufacturer on the planet. Racelogic's UK Web site has tons of data on the accuracy of this technology.