Actually, unless he just got it fixed it DOESN'T fit perfectly.
We had a meet here in Toronto a few weekends ago, and we were talking Bak products.
I'm having problems with my F1 cover and he was having problems with his Roll-X.
I actually think his problem was with his bed extender and the Roll-X, but I don't recall if he had other issues or not.
Agreed that you should reach out to fastNugly (Andrew) as well.