I used to use the metal KTC drums (stab a hole in the top and it flows quite quickly) but they're more expensive so I now use the cardboard boxed plastic containers.
Their opening is much larger so no problem with constant pour, the only thing to remember is to tighten the lids when you buy them as they can leak if they fall over.
Being cuboid they fit well in the boot, or two will fit infront of the passenger seat.
Increasing the fuel capacity of the car, I'd look at getting a boot tank made up the same shape as the boot floor and say 5" high, so that it sits under the boot lip still. Don't forget to take into account access to the spare wheel hook!
Piping it into the main tank probably wouldn't be that hard either under the back seats.
Probably have something like the fuel return going to the boot tank, and a feed from the boot tank to the fuel return spigot on the main tank.
Otherwise there may be a way of going direct to the filler pipe, so when you fill the main tank it "overflows" into the boot tank, then as you use fuel, the boot tank drains into the main tank keeping it full.
That way you'll know when your boot tank is empty by your fuel guage finally dropping
Carpet the top of the boot tank and no one will really know it's there.
You'd even still be able to put the back seats down, you'd just have a 5" step.
Anyone want to do some quick measurments as to what the potential volume of the tank would be?
The added weight (in my experience) will help with ride quality, at least on the estates, and with cracking the rear spheres when their time is up
Hmm, build one for Cassy and enter her in that endurance race Top Gear used biodiesel to kill a modern fuel pump.
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