Coronado Island, near San Diego, California, for one.
Sun City, Arizona, though these are golf communities/mega-master-planned communities. Coronado is a better example of a mixed vehicle environment with golf carts bopping around all the time on the same streets.
Coronado isn't a good example. Or at least not one that scales, that's a VERY affluent neighborhood.
The golf cart isn't a replacement for a car, it's one you have on the side. I would argue that its partially because they're easier to park in a very touristy environment