You cannot tell me with GM's or Ford's resources that a "Flying Car" couldn't atleast get made. Now, it seeing mass production is another thing but IMO the big 3 have the tech to make a "Flying D" a reality.The minimum height for a ballistic airframe parachute to work is 250 feet. This will not help you for any of the most dangerous stages of flight, where you are most likely to lose control, have a mechanical failure or enter vortex ring state. Honestly ejector seats would work better.
Building a VTOL that is merely shaped like a DeLorean is slightly easier than trying to convert one, but this is still much harder than a properly shaped airframe which is itself a task so hard that no one has been able to build one yet (Moller demonstrating how much investment and engineering talent you can burn up trying).
Then the weight distribution would be completely off.
What do you think you need to make fans spin? Moving air takes horsepower. Thrust engines get less efficient the smaller the nozzle is, because it forces you to use more exhaust velocity to make up the necessary force, and due to k = mv^2 that means you use more power to generate the same thrust. This is why helicopters use big rotors not tiny fans; it is much more energy efficient, and they still have engines rated >500 hp. The only reason light aircraft can fly with relatively low powered engines is that the wing acts as a huge thrust multiplier, causing a large amount of air to experience a small downward velocity change. Aircraft that can hover on their propellors (e.g. a few stunt aircraft) need an order of magnitude better power-to-weight ratio than typical light aircraft because direct thrust is so much less power efficient.
The Moller M400 needs 700 hp just to hover in ground effect, and that is a 1000kg vehicle with twice the intake area you are proposing.
That will not 'clean up the air flow' (which is not necessary at these pressure ratios), rather it will add lots of parasitic drag and increase the power requirements even more. The 1957 Hiller flying platform needed 80 HP to hover for a 250kg vehicle, but that was a direct fan with again more than twice the intake and exhaust area you are proposing, and no power-sapping ducting.
You think that because you are hopelessly optimistic and haven't done any actual calculations. The fact that many many really talented aerospace engineers have failed to make a 'flying car' type vehicle for the last sixty years despite huge funding and not having the major restriction of making it look like a DeLorean should be telling.