i think the biggest problem you will have even if you work around the support beams is that our roof is not flat.. so you will have to find a way to flatten out the ridges on the roof so that they look nice and dont leak
as far as i know everyone who has done a sunroof on their VX has stopped it before getting to the ridges on the roof, dont think anyone has tried cutting through them
edit.. just re-read the post, guess you already mentioned the ridges on the roof.. i am curious to see what you could come up with for that