Those are intended to contain liquid fuels, not gaseous ones under pressure. If you want an impact-proof gas cylinder, you will find they weigh more than the engine of the car does, empty.
To give you some idea of how long this has been promoted, watch this very early 80s video:
http://www.youtube.com/watch?v=irvktfQvu4M
Those lightweight tanks? Yeah, turned out they delaminated and ruptured after a while, which is why they never went anywhere in the marketplace.
For a given volume tank, you will get far less range on natural gas, as well.
So your solution is to go back to the 70’s and start there? Or maybe it is to just throw your hands up and ride along in your crappy 70’s American car as well? The reason it went the way of the do-do bird in the 70’s and 80’s is because oil was relatively cheap then and there was no will to fund the R&D to refine the concept because Congress had eliminated most and eventually all R&D tax breaks for private investors to use as justification of minimal gains.
Fuel cells are also created to be the inner bladder for pressure vessels as well but most don’t know about them. The intent is to keep anything inside contained while the container it resides in is allowed to change shape even in blunt force altercations. Added to that is the use of propane fueled lift trucks in lots of industrial and distribution settings so it is not like nobody has been pushing this technology forward since the 70’s.
So, do we also ban the delivery of LP or propane because someone might hit the truck while texting, farding or painting their fingernails?
All that is required is the need for anything and the brightest minds in our country will find a way to deliver. Keep the government out of it and instead releases the entrepreneurial power of R&D tax breaks and it will be solved very quickly if it has not been done already for a totally separate industry. Doesn’t that also sound like something that Pickens would invest in?