They were like a party line.

One day I was at my dentist's office and he asked me about my wife, Savi.  I said my wife's name isn't Savi.  He said I clearly heard you talking to her yesterday on the cell phone.  (She was an escort I knew then.)

Talk about awkward.

I stopped using the cell phone for hobbying until the digital phones came out with the encription.

Ok, A; bluetooth works on a completely different "frequency" than any standard radio (likely the bluetooth capability in the car was left on and reconnected when within range - although that doesn't explain the time lag) so cannot pick up a bluetooth signal. Two; unless you folks know of some place that you can go an get a disposable phone that doesn't require you filling out paperwork, all of them are traceable to you. C; due to the Patriot Act, you cannot legally buy a phone in the US that isn't registered to an individual that doesn't provide a proof of identity. Therefore, all phones are traceable (often by google) to the registered user. 4; if you obtain a phone by other means, you expose yourself to far more peril due to theft of identity issues/laws than you would by purchasing one in your real name.
This is a perilous path you choose and, if you really think a "hobby phone" can protect your identity, you're very likely making an assumption that won't prove to be true. There is no fool proof way to remain anonymous, just mitigation steps you can employ to delay your demise.

JC

save the blue tooth for your family phone