I don't remember seeing this specifically, but it's basically a child booster seat / backpack so I would think it would be fine to use both when driving or flying. Hope that helps, but I have only used it for driving and it's great for this.

We used it only for a car. And for the flight we took it as a bag.

Unfortunately, we do not know this, as the item is sold out. If and when it will be available again is unfortunately still unclear. Please excuse us.

Unfortunately not.

Unfortunately the Rose one can no longer be delivered. It has been sold out and cannot be reordered anymore.

According to the manufacturer, it can hold 8 litres: https://www.trunki.com/faq

The empty Trunki weighs 998g.