How to mount roof rack basket
 

I have the universal roof rack basket i had on my s10 blazer. Meant to U bolt clamp to the factory roof rack. Blazer is gone and i want to install it on my ranger. Trying to think of a mount setup to attach to to the roof or have it hover over the roof via bed mount. Obviously i cant rigidly mount it to both the bed and roof as they would flex differently when going over bumps. Ive seen several other pics of people having these on thier rangers but cant tell how they mounted it... Eventually I will put all sorts of lights on it but not yet.

Any pics/help/ideas?
heres a mock up:
by https://www.flickr.com/photos/150894781@N05/, on Flickr
by https://www.flickr.com/photos/150894781@N05/, on Flickr

Ive thought about building some kinda headache rack and an upper support but i have since added a tool box so i cant run rear supports down as easily as i could before...