I also wonder how much useful space is left in them after the slide-out steering mechanism, batteries and motors.
I'd be more worried about tons of lithium batteries made to the cheapest price going inside the cargo hold.
They weight about 10kg though. It means if the airline imposes a limit on the weight of a carry-on, you probably won't be ably to put anything inside of it. But because the battery is removable, you can still check it in and keep the battery with you.
looking at the image in TFA, that looks about the size of a carry on which is much smaller than I was imagining. to counter, there's a Visa commercial running as part of the Olympics with Simone Biles next to her suitcase which is as big as she is. It is disturbingly large. Like, it can't be real, can it? Or she is just that little. Either way, I'm remembering the wrong parts of their commercial, but I could see a suitcase of that size being something Transformer-ish into something you and your family could ride
She is 4 ft 8 in (142 cm). She's almost carry-on sized herself.