Radar vs GPS: GPS Wins!!!
/A 16 year kid got a speeding ticket for 62 in a 45, but the GPS tracking device in his parents put in the car showed his more accurate speed, first the court ruled against him, but when the "expert" realized the GPS was accurate to 1mph of the speed, they overturned it. http://hothardware.com/News/Speeding_Radar_Gun_vs_GPS/