I was thinking the exact same thing. I wouldn't mind investing in Lilium. They have the best concept for a "flying car"-type vehicle I've ever seen.
The amount of regulations that go into flying cars will likely BK the company. If not, then it'll only take one accident of a "flying car" to fall from the sky for investors to freak out. Let's see, who should I trust to build a car for my family of 5? GM, Ford, a new startup? Even if Tesla built one tomorrow I wouldn't touch it until at least 20 years later when the company has shown it is by an order of magnitude safer than driving. Yes, currently airplanes are much safer than driving, but when you add an extra 10,000 flying cars to a city full of drunk and maniac flyers racing from point A to point B... no thanks, I'll take the long route and drive, and no way I'm going to allow that thing to fly over my neighborhood.
Some immediate regulations I can think of right now:
1. Windows must always be shut while flying, so nothing can "accidentally" fall out and clunk someone on the head.
2. Landing zones must have operators just like airports regulating how many vehicles can land at a time.
3. All vehicles must be inspected at a minimum 3-4 times per year to ensure parts are functioning at high levels (similar to airplane inspections but with less rigor).
4. No fly zones: over schools, stadiums, theme parks, down-town where there are a ton of pedestrians/skyscrapers. I don't want to see Sept. 11th happening again. It's bad enough that terrorrists are using cars and trucks, but flying cars where there are minimal police security? No thanks.
5. Taxes. Luxury taxes similar to owning boats.
6. Repairs must be with OEM parts only, no knockoffs.
7. Insurance policy holders must be insured up to a minimum of $500,000. Drop one of these things in a home in California and that's the average home price. This does not even include injury liabilities. Drop one of these things on a public mall, and we're talking millions in liability.
8. Licensing: required minimum of 40 hours (similar to helicopter pilots) through an accredited flight school.
Yes it looks fun, but the consequence of one of these flying cars going "bad" can ultimately result in not only your entire life's savings flushed down the toilet, but also losing your life and killing innocent bystanders. Is the technology there yet?