Auxiliary fuel tank in front of the slide in camper

Yes I was a little concerned about if I were to get hit from behind if it would knock the camper forward and squish the tank...nOarp, I looked into replacing the OEM tank and they want about $1500 just for the tank, was a little more than I could afford...supercharged, I was also thinking about fabricating up a tank or two to go around my wheel wells but I imagine that might be costly too? I can weld but not that good...