Well there's a new show on BBC called Torchwood (spin off from Dr. Who) and they have this Range Rover with blue led tubes on the front pillars..

I've attached some screens since a video is heavy in size.

Its like on each pillar is a tube light (ccfl maybe) and inside each tube is 3 small lights. These small lights blink in sequence illustrating the police effect.

Can I get these somewhere?