The street racing was only ever part of the gangs skills. From the start it was based around a heist, an undercover cop who also liked to race, and gaining respect amongst the streets. 2Fast and 2Furious continued that trait. If, the franchise hadn't drifted (no pun intended) towards car skills and stunts, it'll been about street gangs, drive by shootings, getaway cars (which did play a joke on bank jobs in Furious 6). Think the right theme was there already, only whoever put ideas into actions thought "how can I do it differently, better, and unique". We had a car in space at one point.