bait car 

A vehicle, monitored by the police, that is used to tempt a car thief into stealing it.

The Vancouver police operate with "bait cars" to trap car thieves. The vehicles, equipped with disabling devices and global-positioning equipment, are parked in a lot where thieves have been active. The bait-car program is well known to car thieves, who consider the practice unsporting,

bait car by JRob November 18, 2005

Baitcar 

(n.) A vehicle which has been modified by law enforcement agencies to detain any person trying to steal (or jack) it. Usually fitted with an engine immobiliser or remote steering device, concealed cameras and door locks which can be locked by remote. A baitcar does not violate anti-entrapment law as the individual is not enticed into stealing the vehicle.

I got caught jacking a baitcar, got me sent down for a stretch

Baitcar by JediAndi September 12, 2005