That fear is a load of crap, man. Think about it, you'd have this same problem in a side-impact collision, wouldn't you? It's a lot harder than most people realize to burst a gas tank AND ignite the fuel in the same crash.
Besides, if you're THAT worried about it, you probably shouldn't be doing it, BUT - you could always just use rubber tubing or something instead of wedling up a pipe. Don't know how good of an idea that'd be, but it would work.