The adapter from Crutchfield makes a double-din head fit very nicely.
The problem is that it relies solely on the dash for support and would move when bouncing around in the Jeep. There is a bracket in the dash that has to be removed to make room for the new head unit. This bracket supported the back of the factory head as well as the top center of the dash (storage bin).
I cut the bottom off the bracket and ground it down in a couple of spots in order to retain it. (sorry, no pics)
Once It cleared, I re-installed it and used a large hose clamp to secure the aftermarket head to it. The clamp runs around the bottom and sides of the head unit and then over the tab for the storage bin screw.
No movement at all.