Anyone ever used a fibreglass tank. I cant imagine they make much sense for an offroader, one rock and you have a splintered tank with fuel gushing out. http://www.ebay.co.uk/itm/321702292577
And only more ethanol are we going to get in our fuel as well, it's what those in Brussels want. It eats the majority of rubber seals and gaskets in fuel injection too, avoid it.
I run a 43l ethylene HPN tank at the moment and when full its Fekkin HEAVY - I cant imagine the strain put on the front mounts (very small mount area) of a brittle 'glass tank. And I would imagine it would crack like an eggshell if you dump it while full as well.