The next time you spot an outrageous bargain at a second-hand car lot or online, think again.

It could be a Frankenstein car, a written-off vehicle that thieves have brought back from the dead by using parts from other cars they’ve stolen for that very purpose. 

These motors aren’t usually well put together and can seriously endanger the safety of unsuspecting buyers and other road users.

You might wonder how thieves are getting their hands on these cars in the first place. It starts when a car is written off by an insurer, not because it is beyond repairing, but because it wouldn’t make financial sense to do so. Gangs buy the written-off cars from salvage auctions. There are around five times more repairable write-offs available than there are parts to fix them, according to the West Midlands police, which says this ‘salvage imbalance’ is encouraging gangs to steal cars for the spare parts they need to fix up the write-offs and make a big profit.

These criminals take advantage of some loopholes in the law, which must be closed. Cars brought back onto the roads after having been written off don’t even need to have passed any official tests, beyond the scrutiny of the repairer. And worse still, a write-off doesn’t invalidate a vehicle’s MOT. So, on paper, they may still look rosy.

It’s not just high-end cars that are being cobbled back together this way. I heard one story about a new driver who had an accident in a Fiat 500, unaware it was a write-off salvaged by criminals who didn’t bother to put one of the airbags back in properly.

This type of crime is part of a broader rise in car theft, which shot up by 57% to 89,000 in 2017 after declining for more than two decades.

But what can you do to ensure you don’t fall for this crime? The advice from the Police is spot on: if you are going to buy a car that’s much cheaper than similar models elsewhere, then ask yourself, is it too good to be true? Do your homework and check the vehicle’s history. If you find out it had been written-off in the past, see if the seller will admit as much. If not, stay well clear as they are either lying or don’t know.

Some action is at least being taken. West Midlands Police, for example, have launched a crackdown on the back-street garages where stolen cars are being processed. We in the insurance industry, led by the Association of British Insurers (ABI) are working alongside the police to help find a solution to this issue.

Rob Clark is niche motor underwriting manager at Ageas.