The flying car designs I've seen have no true redundancies. They look like they would be dangerously unstable if they tried to run on fewer than all motors.
The Volocopter has 18 rotors (fixed, electric motor, with 1 degree of freedom - doesn’t get much simpler) attached to 9 battery packs, and at least 4 can fail (even more when they are “nicely” distributed) and it's still controllable and landable. And they could still throw in a ballistic rescue parachute.
Unless of course the power supply fails, in which case we're back to the point I brought up earlier - you have neither autorotation nor gliding to fall back on, the vehicle just falls out of the sky like a brick - the parachute would help but I'm not sure how feasible that is.