BMW Tail light woes

I'm getting sick of this shit...

The one on the right is the original, cracked and scrapped. The one on the left is the replacement, which I reinforced with metal strips on the inside of the housing and where it attached to the fender... No avail.

Now I'm just going to lose the cheap, stock, plastic crap and go with an old Hella aftermarket piece and fabricate my own mount out of 18 gauge. Also losing the rear fender, but I think I'm going to pick up some stainless sheets to protect the seat and battery along the subframe