And those rocket drones have a significant proportion of their mass as reaction gas for the thrusters, everything else being designed around lightness, and can still only resist gravity on the order of a few tens of seconds before a full recharge needs to be done. They're very much designed for "small" course corrections outside of atmosphere, or quickly dodging the terminal phase of an interceptor, rather than efficient velocity change.

There's no getting away from the rocket equation - reaction mass is heavy. The sheer number of design compromises that need to be made to allow a cold gas thruster system means I can't see anything but ending up with an awful car for the sake of a few seconds "air time". And the rest of the time you'll still be (at least) doubling the mass of your car from the propellant plus whatever the thrusters, tanks, linkages and everything else weights. I guess you could leave it empty, then only charge it for the "Party Trick", but it still seems a lot of compromises for the occasional "Hey, this looks cool".

And then really only usable in a nice empty, flat, controlled environment - the "real world" driving experience has things like other cars, people, buildings and street surfaces that likly wouldn't appreciate what are effectively localised hurricane-force level winds from the car next to them.

This is a car rigged for a specific stunt. And there's a reason why people don't just drive around rigged stunt cars. They suck as being "cars".