The most recent incident occurred on Tuesday 11 September where the offender made off with a Land Rover from a garage in Solihull.
In all cases, the offender has been on a test drive of the vehicle. During the drive, the offender has asked the salesperson to demonstrate how a part of the vehicle performs requiring the salesperson to leave the car.
The man in the CCTV image is described as Asian, between 25 and 29 years old, medium to stocky build, around 5ft 10ins to 6ft tall, with a goatee beard, a gold tooth in front upper row and two gold earrings in his left ear.
Police are urging the man or anyone who knows him to come forward. Anyone with information should call Solihull police station on 0845 113 5000 or crimestoppers anonymously on 0800 555 111.