I bought one of the 150l/min ebay compressors, it is quite large, I was originally planing to put it behind the panel on the passenger side however it was to big so i put it on the drivers side.
I have an external spare tire carrier so I have unrestricted access to this area
It was straight forward, first you can see I cut the panel indent out
Then I unbolted the base plate from the bottom.
The base plate was then attached to a mounting bar that ran from the main seatbelt mounting bolt, to the body just in front of the tail light.
A second switch was mounted in to the base plate, the switch in the handle of the compressor is just left on.
The base plate was then re attached to the compressors side, bolt pattern is the same.
I then made a cover out of MDF. The cover attaches using 2 (rare earth) magnets onto the mounting bar.
I then stuck some Jay car sound adsorbing mat I had laying around on the out side.
As a Bonus the air line fits into cavity in the rear quarter panel cavity out of the way.
In time I plan on putting in a air receiver, a pressure switch and a external air jack.