wiggerman- your are mostly right bout that, tho we dont amplify the signal to send it back. on Aegis ships, we know when were bein active jammed and we can still get range and bearing of whatevers jamming us so we can still shoot it (home on jam). but there are many ways to fool radar, like build a car out of RAM (radar absorbing material). or if you dont have a stealth in the garage, you can use tin foil in your front grill or wrap some around your rims (tell everyone its the "JDM" look)which will scatter the signal. what makes radar accurate is the sensitivity of the device, you dont have to jam or scatter the whole signal, just enuff so that the return is ignored. the problem that i would see with active radar jammers is that, in case no one knows, radar uses microwave frequencies, in the Ghz for surface search im not sure about police. so if you transmit X, K, Ka, or whatever from a unit mounted inside your car, you could be microwaving yourself and whatever else might be in the car (food, animals, etc.) which could ultimately lead to cancer or messin with your reproductive capabilities. (i know alot of radar techs that can only have girls). ultimately, id just buy a decent detector like the valentine or a bel if you dont have 3 bills, and keep your eyes out when your bein stupid.