I love the M5, and I don't mind the fact that is sucks massive amounts of fuel, but filling up every other day or two really sucks. I would gladly pay a few thousand dollars to have a custom fuel tank built and installed in my car. Does anyone know if this is possible, or if there is room in the chassis? I would even be willing to give up some trunk space! Does anyone know a shop that makes safe, high quality fuel tanks in SoCal or on the West Coast? Increasing the tank capacity by 50% would be a HUGE improvement. :confused3