Depends on the state, but i know here in New York police officers are trained to judge speed on eyesight alone and can and will write tickets just by pacing your speed. totally legal and will stand in court
Personally i would skip the trouble of going to court and just pay the 30 bucks unless there are points involved...
2006 G6 GTP Coupe
6 speed manual, white
Black eyelids, 10000k HID kit, aftermarket 18" rims, tinted tail lights, Cold Air Intake, custom straight piped exhaust from the resonator back, partial debadge, black arrowhead overlays, 20% front window tints, 5% rear window tints and tint bar, 12" Pioneer sub in sealed box, 1000 watt amp