wheel clamp 
British
noun
A device for immobilizing an illegally parked car.Don't try to remove the wheel clamp yourself as you can be accused of causing criminal damages....
- It pays to read the signs before leaving your car in a car park or other private land in England: security guards can impose enormous instant fines, and enforce them by immobilizing your car with a wheel clamp.
- Laurent wasn't very lucky after ending up with a wheel clamp on his Chrysler Voyager people carrier and a £120 fine for failing to pay and display.
verb
(wheel-clamp) [with object] Immobilize (an illegally parked car) with a wheel clamp.A nurse whose car was wheel-clamped on hospital grounds as she dealt with an emergency has threatened her bosses with legal action....
- They will wheel-clamp your car if you don't move.
- The vehicle was wheel-clamped by Carstoppers for parking across two bays on a private car park in Haworth.