If the Liberty had as clean a nose as a 1975 VW Golf/Rabbit (which it does) the forebody flow would be fine

And the flow over the roof is good such that aft-body mods will have a good 'source/onset' flow

The wake is the issue

The wake almost 'tells' us what it wants

Your receiver hitch mounted cargo carrier can be the foundation for a boat tail.You'll be surprised by its effect,even at limited length.

They're kinda like a blow out preventer which minimizes an oil spill behind your JEEP,keeping more fuel in the tank.
