Hagerty has a very good walkthrough video with Lars and it looks pretty real. The thing they failed to mention was that the "flying" version is separate and the entire passenger seat is replaced with a pressure tank.

https://www.youtube.com/watch?v=22rvpUecLts

Still frames showing the underside appear to show that it is basically hollow, so fake.

Making a car with a heavy EV battery and powertrain fly like that is probably not something they're able to do.

I think it's not that difficult when you have full access to SpaceX know how and infrastructure.

My only issue with it is that beyond being impressive and very cool, it's pretty useless.