In some US states, it is illegal to employ a radar detector in your car. However, if one were to employ some sort of multi-purpose radio analyzer which just-so-happened to include radar and have a programmable alarm system in it, it may be overlooked or explained away. It would of course have to be able to tune to FM/AM/UHF/VHF/WiFi or something useful in order to be legitimized. Now, I really do want it to be multi-purpose and not just be capable of doing other things. That way, it could be good for wardrivers and real radio analysts who would want to build/buy one for non-radar purposes.
My question is, what kind of device should I be constructing to accomplish this, and what resources can you direct me to to begin learning this myself?"