Yes I made the mounting plate out of a piece of scrap metal I had laying around. My cousin has a metal break, so we bent it like so:
I used 8 self-drlling screws about 1/4" or so, predrilled the holes then wound them into the sheet metal under the interior panel.
I figured there was substantial support there if there was a tire mounted in that spot. It works very well and is solid. I did install a brace from the compressor mount up to the tank mount to stiffen it up more.
Everyone warned me that it would be too loud in the cab, but I don't find it bad at all. For my lockers, it never comes on. I fill the tank and leave it. I bet I could engage and disengage both ARB's 100 times before the compressor comes on.
When I'm airing tires back up, I'm outside the vehicle anyway, so it's not an issue.
I have noticed that it gets hot after awhile. I aired up 2 rigs in a row from like 12 psi to 30 psi, 32's & 33's and it got pretty hot, so be careful how you mount it.
I did modify the intake for the compressor by drilling small holes around the filter so it could draw more air, too.
I'll get some new pictures of what I've added & post them sometime soon.