Gullwing doors are great. I own a delorean and here are a few things I've noticed.
One, I don't have to worry about how close someone parks, I only need 11 inches to open the door.
Two, if it is raining, the door tends to keep my seat more dry and myself as there is less movement out of the way of the door to get around and in as you would do with a normal door.
With the engine being mounted in the mid to rear end, you have a firewall that would get pushed into the flat of your back if you are against it assuming hit from behind. Having a head on collision the delorean's front will crumple as it is just empty storage space. Current cars the engine get's shoved into the firewall which then has a chance to crumple the footwell area that your feet are in.
It is sad that two cars, both with designs to benefit people, have either been destroyed or had their reputation destroyed so no-one would contemplate building anything that even looks like it or has safety features.
I'm sure others can point out even more similarities and benefits.