Radar Detectors.

http://www.guysoflidar.com/museum/foxxk_1.html 

What started it all (that I can remember)

http://www.guysoflidar.com/museum/fuzzbusterii.html 

The king of radar detectors IMO back in the day, and looked like it was designed specifically to fit near the a-pillar of a 7 series BMW.

http://www.mem-tek.com/radar/vintage_radar_detectors/Escort_1000x480.jpg 

High school kids used to steal these quite a bit and sell them to other classmates. I had a friend who stole one of the original Fuzzbusters (link #2), and couldn't help but laugh since it was pretty much an antique already at the time (early/mid-80s). I bought an Escort from a guy for $50. He and his friends later got busted, and I had to give it back to them so they could give back to the police whatever they could recover from their "clients." Of course, after the fact, people told me I should've kept it anyway, but I was being a good person...except for the receiving stolen property part. 🙂

This is the one I used, and currently still have buried in a box somewhere...pretty useless once laser came out. I don't think mine had that capability.

http://www.mem-tek.com/radar/vintage_radar_detectors/Cobra_Trapshooter_Micro_RD-3160_1000x400.jpg 

Not useless at all. Most states still use radar as the primary speed enforcement method. For one reason, the cops in NJ like to drive with their radar on, I don't think they can do that with laser.

I use a 10 year old Bel detector and it's definately saved my ass a few times.

I wouldn't use my old radar detector. If I buy another detector it will be a Valentine.