Thanks Arjan! The fabric sides were good for summer use, and when it wasn't terribly windy, but not a lot of fun in the winter. The hard sides are insulated and dry, and despite a few hours of pretty strong gusts on the North Coast straight off the Atlantic the van just rocked a wee bit but no creaks or groans or leaks so I'm really happy. It was a really awkward addition with a lot of experimentation to get the various aspects right.