What would happen in a crash?
I'm not trying to put a dampener on your achievement,.. but the restraints I see on those barrels seem minimal. a 20mph collision would prob be plenty enough to send them flying at the back of your (and your passengers) heads, probably killing you both!
I'm not suggesting spending thousands on a brand name crash tested system,.. just pop down your local engineering place and get them to weld up a cage for them and bolt it to the chassis.
As it stands, I'd not hesitate to use the word "deathtrap"!
I don't mean to sound harsh, but WFP is about reducing risks not replacing them!