The PSNI attached wheel clamps to 57 vehicles in Derry this week.
The operation took place in the Waterside area of the city on Wednesday and Thursday.
The reasons why the vehicles were clamped included no tax, no insurance and no M.O.T. certificates.
"Question: What have Audi, BMW, Citreon, Landrover, Lexus, Mercedes, Renault, Skoda, Vauxhall and Volvo got in common?
"Answer: no tax," wrote the PSNI on social media.
"Fifty-seven clamps were attached to said vehicles, 11 tickets issued, seven tickets for no M.O.T. Certificates and two reports for no insurance to the P.P.S. (Public Prosecution Service)."