A simpler concept from EHang, a Chinese manufacturer of consumer drones, is similar in general configuration to the Pop.Up, but omits the roadable portion and the fan shrouds (which double, by the way, as people protectors). It was claimed a while ago that you would be able to hail an EHang 184 PAV in Dubai in 2017. I doubt this has come to pass, but as Pliny would have said, something new is always coming out of Dubai.
A fundamental problem of multirotor designs is the conflict between compactness and disk loading. The single-seat EHang fits within a 15-foot square. Compare the EHang design to the Robinson R22, its conventional-technology equivalent — bearing in mind that the R22 is a two-seater. The R22’s 25-foot rotor sweeps 497 square feet and the helicopter’s gross weight is 1,370 pounds, for a disk loading of 2.76 pounds per square foot. This is on the low end for helicopters but allows the R22, which uses a 360-cubic-inch Lycoming engine derated to 124 hp continuous, to perform well with relatively little power. The R22’s power loading for takeoff is 10 pounds per horsepower.