Square-cube scaling being what it is, I think it'd be much more reasonable to use propellers (like quadcopters) than try to scale down COPV's to a Vroomba! size. That's actually an interesting product idea. A small flying vacuum cleaner could clean a variety of surfaces; not only floors.

(And you could even mount the charging station on the ceiling, so it doesn't take up floor space).

https://www.amazon.com/window-cleaning-robot/s?k=window+clea...

Fan cars are pretty old. From that perspective, the driving upside down part is "less impressive" but screw it, still cool.

I want to see it on a track going all out, but something about what they decided to focus on tells me nobody gives a damn about this actually doing anything performance car related.