Flexible Gas Container/Tank/Bladder for Stowing in Tight Spaces?

[rbeau30]

I searched for "Flexible Fuel Bladder System"

http://justgastanks.com/product_info...44afe29391b925


http://atlinc.com/pillow.html

[HoneyBadger]

I searched for "Flexible Fuel Bladder System"

http://justgastanks.com/product_info...44afe29391b925

$325??

Definitely not in my budget, and 14.5 gal is too big to handle.

Maybe I didn't describe my needs well, but I need something that I can pull out and use to refill my vehicle's main fuel tank when needed (generally only in an emergency or to rotate the fuel out to prevent it from "going bad")