RoboCar might be possible. How would you envision using it? Currently, RoboTank requires blue circuit, making it mid-game technology. Are there mid-game situations you would want a RoboCar instead of a RoboTank, or are you wanting an early-game version?
Also, one significant technical problem is that cars can't easily drive through trees, meaning RoboCars would get stuck much more than RoboTanks do. I think the logic for dealing with getting stuck would need substantial work to make RoboCars viable due to the tree problem. Frankly, that seems like it would be more work than is justified by the marginal utility of a RoboCar, but perhaps you see a use for them I haven't thought of.
The other area I envision requiring work is that all of the self-driving parameters would need to be re-tuned for the car's handling characteristics so they stay in formation without crashing into each other a lot, although that's probably not too much work.
Of course, if someone wants to try implementing RoboCars themselves, I'd be happy to advise and to review pull requests.