The man had earlier been arrested for driving while forbidden about 9.15pm on Wednesday, the Manawatu Standard reported.
A constable put the man in the back of the patrol car before going over to his car to take down its details, Senior Sergeant Brett Calkin said.
“The offender got in the front of the car and drove… for a short distance…and then ran away from the scene.”
Police are still looking for the man who would likely face charges of driving while forbidden, escaping police custody and unlawfully taking a vehicle, Mr Calkin said.
The man was not restrained when he was put in the patrol car, he said.
Offenders should probably be handcuffed, and police were investigating the incident, Mr Calkin said.
The latest incident came just five months after an unrestrained 18-year-old man escaped from a parked police car on Palmerston North’s Park Rd.
Police found the man an hour later.