Is anyone looking at a fuel tank inside the center of the car? The current center tunnel is unstressed, some creativity should yield a very nice capacity tank down the center... Like my old Fiero, it's a very safe location, Run all the wires down the sides of the car and the shifter on top of the tank. Use 1/8 aluminum to make up the tunnel instead of the tubing and thin aluminum.. Add a tank behind the passenger, and use an external fuel pump, allow swapping from one tank to another...