The code that John Doe uses to operate his vehicle, which he speaks aloud in the second episode of season 1, is the code used to unlock Unlimited Health in Twisted Metal 2: L1, R1, Up, Down, Left, Right, Right, Left, Down, Up.
Granny Dread is based on the character of the same name from Twisted Metal 3. Her stuffed dog is also featured in her character bio in the game and makes an appearance in the TV series
In one of the season 1 episodes, the kids are playing with RC toy trucks that resemble those used in Twisted Metal: Small Brawl
Carl and Jamie Roberts are based on the characters Outlaw in the Twisted Metal games
Mr. Slam is a playable character in Twisted Metal 2, driving a heavy construction machine that slams opponents with its forward-facing jaws.