Assuming we're talking about a scaled-up multi rotor concept like the ones Airbus and others have been showing, then I think the biggest design and regulatory issue will be noise abatement.
Scaling up a conventional drone to carry two pax will not be a quiet vehicle. It will be as annoying to anyone on the ground as a helicopter, and helicopters are only allowed to operate freely in urban and suburban areas at very low altitude and landing permission for police or HEMS flights.
There are other issues like safety, liability, legality of overflight of private property, etc. But the main one is that anything based on current technology will be too damned loud for anything but protected flight corridors and restricted launch/landing areas, which limits the usefulness. The entire fantasy of the "flying car" is predicated on free flight, but it won't work like that.