Theres only about 6" between the bumper cover and the trunk pans. I was able to complete the work with out removing the bumper cover but I earned a few nice scratches doing it. I would recommend removing the bumper cover for anyone else, it will make for a better project.

I removed the trunk molded interior to do the inside work. Then bolted the hitches to each of the trunk pans using oversized 1/4" steal internal backing plates on both the horizontal and verticle tie points to distribute the load. I JB welded the backing plates in place to ensure that there would never be an issue of anything coming loose, shifting or rattling.

It's way over done for the load that I will be pulling, but that's just the way I am. The SLK 32 uses the same set up but only 1 centered hitch to carry the same load.