The rear stabilizers actually go toward the center behind the Electric jacks.
Here's a few photo's of my install:
Click HERE for a few more photos
I tried the method they list in the instructions for the rear install when the C channel cross member is covered by insulation. ( Drill smaller holes, use the self tapping bolts through the stand-offs). A few problems with this setup.
1. The self tapping bolts were a major pain in the rear to get going. I had to use my screw gun on 'Drill' speed to get it to finally catch.
2. One of them stripped completely.
3. The ones that did hold, didn't seem to provide movement free mounting.
So, I took those out and went a different route. I used a utility knife to cut a flap out of the insulation material ( corrugated plastic cardboard look'n stuff ). Leaving one side attached. I cut this flap starting at the back edge of the C Channel cross member (found by poking holes through with a small drill bit), toward the front and big enough for me to get my hand into with a wrench. I then followed the instructions provided for installing with an Exposed C Channel ( swivel bolts up through the C Channel, with washers and a lock nut on top ). If you go this route ( which I recommend ), I strongly suggest that any tool you put up inside the 'belly' be attached to a safety line. I dropped one boxed end wrench in there twice and had to fish it out with a magnet...
Once you finish the install with the above method, fold the flap back down and cut out just enough of it to allow the flap to close securely. I've thought about sealing it with some sort of tape, but I don't really think it's necessary as long as you have a tight seal that will hold the flaps closed.
Hope this helps!
LK