I wanted to add some things.
We just got back from our 1st long trip since I installed the top. I really must say this top is great, all i needed was head room for standing not sleeping. If you need sleeping I would not do this type.
It doesnt leak and there is no wind noise up to 90mph.
This winter I let the snow build up on the roof at 4ft I inspected every inch no leaks not even bowed (I did the string from roof to floor test) from the weight no problems at all. ( it also gave me a good idea what a fixed roof would look like) It seems to have rained every day since Oct. no leaks while driving in the rain or snow it did both on this last trip.
I all so believe The van is stronger with it (welded the remaining 8in of roof rails to the roof)
When its windy just drop it, or turn the back of the Van into the wind and it blows right over (I had to do that twice on this trip.)
I have not noticed any fuel mileage difference I averaged 19.5 over 3000 miles.
IF you are thinking of doing this or if I can help in anyway please do hesitate to ask. I didn't thanks Jeremy.
I Love My Van