I guess they changed things up since mine is a 2014 model. My bottom bracket was actually L shaped that would wrap across the top of the raised channel. I didn't want to do that so I cut that part off which left just a flat plate. I drilled my own holes in that part so I could screw it in to the side. Not sure how much of a lip you have, but maybe drilling custom holes may give you just enough room to attach the bracket. The top bracket can be rotated so it mounted facing the inside vs the outside. This would place it so it doesn't interfere with your rubber gasket. You would half to mount it through the top. I'm not sure that is a big deal since a lot of them are attached through the top of the lids. If you use small bolts, the carpet will cover the head.
If that doesn't work then I'm out of ideas other than the PVC "lid support" I used for years.