Laws are different all around but the result is the same. These vehicles are highly illegal and any horsing around can become an issue! People seem to not get it, I love the idea of "acting" like the next guy in the movies but only when it is in a controlled environment such as when some of my fellow car owners are brought into shooting a funny shoe commercial:
http://www.youtube.com/watch?v=mWoPybzPUiY
Note the use of "Metro" police instead of Chicago Police as CPD does not condone the use of their name (except in Chicago Code). One of the young officers in the background is an actual CPD officer who actually owns one of those cars. My fellow collectors have also been called to act in Chicago Code, Barbershop 1&2, the old Hillstreet Blues, etc. That's all and no where else!
It still seems to me to be common sense but then again, common sense as of late has not been so common!