Sure, we're talking about a Smart Car Fortwo here but even those will reach freeway speeds if you give them long enough. But for roughly the same price, wouldn't you rather have the most badass jet-ski of all time?
Antigrav will give us flying cars, but more importantly it'll reinvent jetski technology. These seacraft hoverpods look sexier than those pod racers in Star Wars: The Phantom Menace. Plus you could zip up onto the beach and spray sand in the face of the jock who bullied you during high school.