They are all 15-17. They're all friends (since Turbo is no longer the only playable character, he isn't as much of an egoist). Lane and Tailgate were added as 'fem choices', the original Turbotime didn't have have them. Tailgate and Jet have scars from getting into wrecks. All of them crash their cars for fun. And all of them have the easteregg skins like Turbo. Set and Jet are twins, so are Lane and Tailgate. However, the Spinster twins aren't related to the Joystick twins. And Turbo isn't related to anyone. Turbos loud and joyous (in that teenage boy way,) Sets a grouch, Jets mischievous, Lane is also mischievous, and Tailgate is chill and honest.
Easteregg skins; i am NOT drawing this shit bro. I'm too tired. But!! I will tell you this, there's lots of them, but really the only important ones are the sugar rush, fix-it Felix Jr, and classic easteregg skins. The sugar rush skin is a skin based off of princess Vanellope Von Schweets racing attire [the one she was ment to have,,so the cream like ice cream??? One], the fix-it skin is Felix's uniform [each character have their own 'gold tool'], and the classic skins make the teens look like 3d 8bit modles of themselves based off of the original turbotime sprites<--this becomes a problem in the narrative at some point for obvious reasons. All of the teens can freely toggle these skins on and off at will.