Rush. Don't want to take the wind out of your sails but I can't see what all the fuss is about here.
1600MPH!?

Sorry, I'm just obsessed with speed.

...a practical solution that flips a car the right way up when it lands on its head
And yes, I have a great idea for one. (writing it down on my to do list) I'll release a plugin eventually

Really, I don't think this new car is going to make it into my game unless I get some physics issues solved, -such as the wheels sinking into the surface of a ramp or sinking into any curved surface. And obviously AI is going to be a problem.
But sure, I think it would make a nice arcade style car object, but I don't think it's happening without any AI..
Or, I was just thinking; I could combine the existing car with the new car and have it feed off of the existing car object's AI... I'll have to look into that.
But anyway, can't wait to try out the PhysX car. That's going to be awesome!