The Unmarked Cruiser is a police vehicle found in Grand Theft Auto V. It's based on the Vapid Stanier platform, which includes the Police Cruiser, Sheriff Cruiser, Taxi, and the older civilian model (bearing resemblance to Grand Theft Auto IV's edition.)
The Unmarked Cruiser has several police lights. Two lights are located in the grille, a strip is located on the front window, and two smaller sets are located in the left and right corners of the rear window. The front of the car retains the push bar from its marked counterparts. In addition, its taillights flash in a similar manner to the Police Cruiser.
In terms of performance, the Unmarked Cruiser is similar to its marked counterparts. It has decent acceleration, top speed, and like its other variants, it handles surprisingly well for a large bulky sedan. The vehicle can also sustain heavy damage before failing.
As of now, obtaining it is limited, since it's only found in one of Barry's missions. It's recommended that the player obtains a desired number of them, by using this method, before completing the mission.