I removed the crappy thin metal bumper from my 5th wheel and bought a thicker walled 4x4 square tube to replace it. I then weled a 2" receiver hitch to that and to a 2"x2" sqaure tube that is welded to the inside fram rails about 12" or so back.
Then I mount my rear view camera right above where the bikes go so i can watch them on my dvd screen in my dash.
Also the bike rack i have stated on it no 5th wheel or travel trailer mounting. As the one i have bends down to be used on htach backs and such and has alot of movement. So i welded the hell out of it and reinforced with some 1" x 1" square tubing also, thing is complelty solid now and also topped it off with Hitch heavy duty clamp to take all the slop of it out.
http://www.tigerindustrial.com/TH/index.php?main_page=product_info&products_id=52&zenid=9e940d45b4662f4ed568d8e65f8371dd
It is very solid now and i dont worry at all about having the bikesback there.
Hitch clamp was 24.95
All the metal was around $105 bucks with lots of extra left over.