Sharon, it would have to be new cars only. Anything bolted on after manufacture can of course be removed, but something built into the structure can be made damn near impossible to tamper with.

For example it should be possible to set it up so that it will permanently scramble the ignition if anyone tries to access or remove it.

That would then require resetting by an official garage, with a specific computer setup, which would also be required to notify the DVLC or the police.

Simples.

Don T.