My previous boy loved to chase cars also but I lived in an apartment complex with lots of "green" space where we could walk without being near the well traveled areas. There was also a 98 acre (I think that's the right amount) wooded area right next to the complex that was great fun (when it wasn't muddy). Very glad I don't live there anymore as those 98 acres are now a mall!! And the balcony that we had would have looked right to it. Can't even imagine all the basenji craziness from all the activity if we still lived there.
Current boy really doesn't care too much about cars (thank-you previous owners, whomever you are) but he has still run a path in the back yard from running from side to side trying to watch the joggers/bike riders/even just walkers coming down the street…and they don't even need to have a dog with them, although its worse if they do. But he also chases all the squirrels that come to my hickory tree, the bunnies that (I think) live under one of my pines, the neighbor dog, etc.,etc. I'm not sure it can be completely stopped, its their nature, but it can be curtailed. Some good advise here. Good Luck!