The Formula Project concept from Hoversurf uses fold-away wings and 52 tiny turbine Venturi propulsion units for a combination of VTOL convenience, winged efficiency and a compact form factor.
Details are fairly scant at this point, but here's what we know: The Formula Project is a vehicle designed to fit in a single car space, once its wings are folded up. The designers consider this a key point, as early flying car type designs are going to need to work with the way our cities are currently built, which typically doesn't include a lot of aircraft hangars.
Forty-eight small electric thrusters handle the VTOL/multicopter style flight mode. They look like no more than 8 or 10 inches in diameter. These are a proprietary Venturi turbine design; hopefully they work better than Venturi designs do in wind energy harvesting, which is not very well. But the Venturi effect would appear to be minimal here anyway.