Two bogus police officers were caught when they stopped a police civilian worker and demanded he hand over his driving licence.
Nile Rashid, 20, and Usman Sarfraz, 22, drove behind people with a blue flashing light and flashed their headlights at them.
The pair have now been jailed after admitting impersonating police officers.
One teenager and her passenger pulled over but then drove off with their doors locked when they saw four young males in what they initially believed was a police car.
The matter was reported to police when Sarfraz demanded civilian worker James Boland show his driving licence and he handed over his Police Scotland ID badge.
The pair also demanded a third victim hand over his details.
Both men pleaded guilty at Glasgow Sheriff Court to impersonating police officers on various occasions between December 21 and 22, last year.
On Wednesday, sheriff John McCormick jailed Rashid for 20 months and engineering student Sarfraz for 17 months.
He said: “The public has to have confidence those stopping motorists are police officers and not individuals masquerading as police.
“This office is particularly disconcerting when conducted at night.”
Procurator fiscal depute Adele MacDonald said just before midnight on December 21, Ciara Heath was driving home from work with a friend in the passenger seat.
The 19-year-old was on Auldhouse Road in the south side of Glasgow and became aware of a car driving behind her flashing its lights.
Ms MacDonald said: “Miss Heath presumed that the vehicle wished to overtake, however, the vehicle continued to remain behind her and continued flashing its lights.
“The passenger looked back and saw a flashing blue light coming from the passenger side and she thought the vehicle was the police and instructed the driver to pull over.”
She said they were “apprehensive and scared” because there was no reason for them to be pulled over.
The girls drove off after seeing four men in the car. Around half an hour later, Mr Boland was stopped on the same street by a car flashing its lights and “operating a flashing blue light”.
Ms MacDonald said: “Again the driver assumed it was a police vehicle and pulled over and stopped.”
Sarfraz got out of the passenger seat and claimed Mr Boland had gone through a red light and demanded to see his licence.
The court was told: “Mr Boland took his wallet containing his driving licence from his car along with his Police Scotland ID badge as he is a civilian driver for the police.
“This was presented to Sarfraz who on seeing the ID badge claimed all was in order before simply returning to the vehicle, which made off at speed.”
Mr Boland noted the registration of the car and contacted police.
Another man was also stopped by the accused and asked to produce his driving licence before being allowed to go on his way.
Police saw both accused that night, with Rashid in the driver’s seat, and took their details but let them go as they didn’t have all of the information.
They were both arrested the following day after more reports about them were made.
It was said on behalf of both of the men it was done for “the amusement at the expense of others” and they have since had time to reflect on their behaviour.