panda car 
noun British informal
A small police patrol car (originally black and white or blue and white).Even if every available officer was sent out in a panda car, the odds of a patrolling policeman coming across a village post office raid in England's biggest county is next to nil....
- I recently saw a police officer driving alone in a panda car using the walkie-talkie.
- It's so grey in London town, with a panda car crawling around