Number plate thieves are being targeted as part of a new scheme to cut crime.
Motorists are urged to use new screws to cut number plate thefts
One-way screws are being fitted to cars in Oxford by the city's crime reduction team following a spate of plate thefts in the past year.
They are available to motorists free of charge from Monday on a first come first served basis.
Criminals are thought to use the stolen number plates to cover up genuine ones in order to avoid paying for petrol or being detected for other crimes.
Recent figures indicate 163 sets of number plates were stolen from vehicles in Oxford in the past 12 months.
The special screws being offered to drivers make it impossible to remove plates without them breaking.
Nick Gilbert, of the crime reduction team, said: "Obviously, it is important to us that the public do not have their plates stolen in the first place, which can be expensive to replace and renders the car unfit to drive.
"There have been instances where the plates have been used to avoid paying speeding, parking and congestion charges and this can cause a lot of problems when the tickets begin to drop on the doormat."
The "clutch head" screws can be picked up from Cowley and St Aldates police stations.