Thanks for sharing. I have a MK2 with a fuel cell using a MK4 cluster. I went with a company that made a custom capacitive tube based sensing system that every other ign cycle reads empty, full, or the correct level. Very annoying. I'm hoping to get this resolved soon so I don't have to drive around with an extra 5gal container of fuel in the trunk.
The baffling inside the cell makes mounting a standard level system challenging.