Rob - do you mean the back 'bumper'? In which case I agree. It's hardly strong enough to even carry the spare. I see people mounting bike racks and other bolt-on hitches and they (IMO) are crazy. I'm trying to avoid that approach.
I'm talking about welding a hitch between the two 6" steel I-BEAMs that run the length of the trailer. They are designed to hold the weight of your entire trailer and everything you put inside of it