Over the years I've had two bumpers stolen but only one radio. Probably says much for my choice of sound systems.;-)
The first was the rear off a Rover P6 just before going on holiday to France, and you wouldn't believe just how many bits it was made up of to replace with new. (I tried for a secondhand one but they were all rubbish) The new one was secured by 'thief proof' wheel type nuts and wired into the alarm...