No they don't, there are special units (e.g. AL Priority) available but the jam laser guns for 4 seconds only, for radar you will get an alarm only and have to brake if you prefer not getting a bill. Cheers Christian
There have been stories of people inadvertently leaving their garage door opener switched on and it causing problems with the readout. Of course you could only do this if you did have a garage door that needed one of these devices.