So why the desire to have a VTOL car right now? The capability to do affordable commuter air is almost in reach and we already have aircraft in the certification pipeline that can fly 2 people on electricity alone for about an hour (see Pipistrel Alpha Electro and Airbus E-Fan). VTOL is something we've been working on for decades and still have issues with reliability (MV-22/F-35 anyone?) but airplanes are inherently stable and incredibly simple once you have a power plant that doesn't suck. If you want to know why GA has been lagging so hard, just about every plane you see has a $30k, 10gph, 258lb, lead guzzling O-360 in it that dates back from the 1930s. And yes, we still use leaded gas (100LL).