It really makes me laugh when these topics arise, diy or fitted? Crash tested? Frames or straps? The reason it is all hyped up is so these companies are in business! How many of you who drive cars have stuff in the back and on the back shelf which is not secured? All these things in an accident can kill you but no one even thinks twice about it!
I'm not saying just chuck a tank in the back fill it up and away you go, but any one with some common sense does not need to be spending thousands on a fitted system. Ask yourself this, you've spent all your money on a all singing and dancing system and have no money to replace your wrotten rusty van, that has hardly any of the floor left under your ply lining, what good is that when you have this accident and it rips it straight out the floor and chassis?
It ain't always about fitted systems, be sensible do it yourself and save money!