it sounds like it would work with a "tamper proof" torx bit. I have them at work (auto mechanic). I know for a fact that torx bits and allen head bits will interchange, just use the right size. if the regular key has a hole drilled right in the center, and the "lock" has a pin in the middle, I am pretty sure a tamper proof torx will work.
you can find a set of little 1/4" drive bits with a little adapter to make it fit on a 1/4" drive ratchet or other handle. they can be quite affordable too. I have a set that I payed less than $10 for.
and, if you have that, now if your car has a tamper proof screw on it somewhere(VW mass airflow comes to mind) you can fix it