they aim where the front licence plate would be. and yes, they can aim for certain parts of the car, considering when most people are clocked, it's at around 500 feet, since that's where they can be for certain which car they shot. and 500 feet from a stationary point, you can aim pretty well. they aim there b/c that gives the most radar and laser echo. they wouldn't aim at glass, b/c it just passes through. the front plate (or where it would be) gives them essentially all the frontal area of the bumper, the radiator (in cases of radar) and the whole reflective matrix of the headlight assembly (in the case of laser)