Cars with faults will be sent to garages in the Isle of Man by trading standards officers to test whether repairs are being done properly.
The Office of Fair Trading said it is "stepping up" its monitoring of servicing and repair services.
Trading standards officers will use second-hand cars, motorcycles and commercial vehicles with fixed faults to assess the garages.
OFT chairman Bill Henderson said customers "needed to be protected".
Chief Officer Nick Black believes that there is a requirement for more intensive checks across the island.
"Work not carried out properly could make the vehicle unsafe - increasing the risk of accidents with resultant injuries or even deaths," Mr Black said.
"Cars are one of the most expensive purchases many of us make and we rely on garages to do a professional job when servicing or repairing them."
The vehicles will be booked into garages by the OFT for services.
The work is being assessed by engineers to establish whether or not it has been carried out to the requisite standard.
The engineers will also assess whether or not garages have charged for parts which did not need replacing.
Enforcement action will ensue if any serious or many less than serious faults are missed or if garages charge for unnecessary work.
Mr Henderson said: "The OFT is determined to ensure that there is a high standard of workmanship at all island garages."