I've seen that done also and it is cool, but I can definately seen where it could be a problem. Getting rear ended could cause the piping to the gas tank to get jarred loose and leak or something. Also think about how you are going to connect the stock gas pipe to the extension. Then only way that would make sense to me is to weld it and good luck doing that. Also if you dont get every little hole plugged up on the connection between the stock pipe and extension, you could leak and even just fumes can be a serious problem.