On one of the episodes its parked up on a side street with Steve Lewis behind the wheel while watching the girls go by. You can see the plate then.

On another note we have drivers coming into work to pick cars up who are ex police. One of which is ex GMP roads policing who was working with the X dept but I a marked up car.(not in the show) He still goes out drinking with Steve Lewis who he says has now retired along with the guy with the big GMP at who is usually with him in the show.
Alan also said there was a couple of RS2000's that got pinched from the police way before the tv show in 1995.