Yes, this is on a TxAvy manufactured rack. I should have given him credit up front, my bad.
The Yakima MegaWarrior dimensions are 52x48x6.5 and I don't think it is installed sideways. It looks like the PICs on the Yakima site.
As far as mounting. Here is a PIC of the rear mounting. I drilled two holes on each side (left and right) of the cross bar to accomodate the UBolts used to mount them. I still have to paint the UBolts black to make them look better. I am also going to get a wing nut similar to the front mount to make it easier to remove. Here is a PIC.
For the front, I was able to use the Yakima mounts. Here is a PIC.
I am going to order the Yakima MegaWarrior Extension that will make the basket 22" longer. While this will make the basket extend about 8" past the tailgate, it will allow me to use the Yakima mounts on the rear, like I did on the front. It will also add much additional storage space.
Yes, you can open the sunroof if you put it on the roof. I went with it in this location for three reasons. 1, I don't have a roof rack. 2, with my 6" lift, I don't need more weight on top. 3, with my 6" lift, I would have a hard time getting anything heavy in it on the roof, without assistance in lifting it.