[Sebb767]

> plugs into your ODBII port

Which is usually quite easy to check. It's not a guarantee, but with someone sophisticated enough to crack a modern car there's a good possibility they know to check the OBDII slot.

[lrvick]

They come with extension cables. You can always plug it in under the dash and leave the exposed one disconnected.

If they are sophisticated and have time to take the whole car apart then you are SOL anyway as they will find any transmitters with an SDR.