In an interview with DMA Design creative director Gary Penn in 2011, he revealed that the police in the game turned out the way they did because of a supposed bug where police cars in pursuit tried to ram through the center of the player's car rather than a specific side, causing their driving to become extremely aggressive and seemingly insane. Penn cited this as the point in Grand Theft Auto's development where it stopped being boring to the developers and became more "dramatic", and they started to focus on general play and "being able to piss around" more than the game's missions.
Head Radio is the only radio station from GTA 1 that appears in other games; it was also a station in Grand Theft Auto 2 as well as in GTA III and Grand Theft Auto: Liberty City Stories.
There are unused graphics for a helicopter. When spawned in-game, it moves on the ground like a car.
After the PlayStation version's successful release, development began on a port for the Nintendo 64. Grand Theft Auto 64 was rumored to have graphical enhancements and new missions, but was cancelled without ever having a public appearance.