A sequel to The Simpsons: Hit & Run was once in the works, but was canned to make way for The Simpsons Game. In an interview with GAME Media (via Gamesradar+), senior game designer Joe McGinn said that his team had been working on "some very early gameplay prototypes."
The biggest change that the potential sequel could have seen was the introduction of connected vehicles, "so you could have a trailer being pulled behind a car with some fun results." Unfortunately, the new game didn't get very far off the ground "before EA won the right to [The Simpsons Game], so sadly there was nothing we could do but move on."
McGinn hasn't entirely given up hope of bringing the game back to life, echoing producer Vlad Ceraldi's sentiments that he "would love to have it myself on Nintendo Switch." McGinn also cited a surprisingly active modding community, suggesting that if people can find a copy of the game, it'll still run on modern Windows devices.
Personally, I'm still reeling from the shock that there was ever a new Hit & Run game in development. There was a time where I lived and breathed that game, but I'd just assumed that it was always intended to be a glorious, single moment in time.