Don't see why not, there's rails to fit bars, though I'm not sure what the weight limit is. You wouldn't want to much weight on there when you raise the roof.
Had a sea kayak on the roof of my Beach today. Think the limit is 50kg which would cover a kayak and surfboard.
The kayak needs to come off before I would attempt to raise the roof. Might get away with a surfboard but nothing heavier.
I am planning a 6 week summer tour - meandering down towards Greece via the previous Yugo states. Thinking i might need a bit more room and stash our bits / bobs on the roof - i have read the existing threads about weight limits etc, but wonder if anyone has some experience of the best style for...