Hmm, I think it will have some obvious problems.
First of all, I think that inflating it by hand will be a real chore.
Second, I think it will leave tiny scratches on the roof because if it has any dirt on it (or your roof) it will just rub and wear directly on the surface. And on a large surface. Worse than the small feet of a regular roof bar.
Finally, I don't see how they can say it will 80kg.
OK, maybe on flat ground it can. Sure.
But there are hardly any cars that can carry that kind of weight on their roof, and only when using 'normal' bars that distribute the weight to the side of the roof, where it is solid. After all, the middle of the roof is just a thin sheet of metal (alu in our case), not designed to take any weight at all. It will just bend.
Using it on an all-glass roof would probably be better because glass doesn't bend or scratch as easily as metal+paint, But I'd be damned worried about a sudden shattering of the roof. It just wasn't designed to take weight.
Surfboard: ok. But stuff from Ikea, as described on the site?! Rather not.
The roofbar solutions for open sky that I saw from Johann also show regular bars that carry the weight on the small metal area that is left next to the open sky roof. Do a search for open sky and/or roof bars / rack (or similar) and you'll see what I mean.
My advice: don't risk it, don't bother.
Edo
P.S. Why doesn't the website show any picture of a real application of these inflatable things? With load and all.... Doesn't work??
P.S.2 The idea is great indeed. I'd love my roof bar to be collapsable in order to keep them in the car at all times...
