I was going to expand on the entrapment angle, but Pringo pretty much nailed it, in that the key is that it's only entrapment if the offence otherwise would not have occurred, if not for police enticing someone into it.
This is clearly not the case for a bait car scenario, because for the offender, the bait car is indistinguishable from any other car parked on the street. If not for the bait car, the offender would still be looking to steal some other car.
As for Baitcar/IMPACT being fake/staged, well....