Indeed it is.
And we can, in fact, have flying cars
. It's not actually that hard to do. The reason we don't have a lot of STREET LEGAL flying cars is because it turns out they're not actually all that practical from a transportation standpoint.
You know what else isn't practical? Hiding a starship on the bottom of an ocean. It's not actually that hard to do. It's just kind of silly, and your chief engineer is probably going to complain a lot about how stupid this is even if you think you have a good reason for doing it.