Comment by gcanyon

For anyone doubting the downforce aspect, that at least has been demonstrated by others:

https://mcmurtry.com/upside-down-driving/

McMurtry says the hard part isn't the suction, really, it's making the skirt work across a variety of road conditions, so you don't lose cornering ability when you need it most. That track Tesla built was very smooth. It's possible they can do what they showed, and not be able to do the same on a regular road.