> I had a strong gust of wind rip the two "rollers" right out of it. 
> Then stress cracked the skylight itself around the hinges.
> Haven't driven with it open since then.

I too avoid driving with the skylight open. Usually it's fine but I have seen exceptions such as the one Bill mentions. As for cracking the skylight, that's actually a "feature."   The original Westfalia design called for the skylight to bend and if necessary crack in the event of stress (exerted either from above, or from inside the van) instead of transferring the stress through the hinges to the fiberglass top itself. Basically a "crumple zone" to sacrifice the skylight rather than cause additional damage.  The OEM skylights we sell (both the dual layer ones, and the single layer ones made by the Skylight Guy on the original Westfalia molds) maintain that factory design. Aftermarket skylights may look similar, but do not use materials that match the factory specs and may either crack too easily or not easily enough (and in some cases also do not seal quite as tightly).

Ron Salmon
The Bus Depot, Inc.
www.busdepot.com