This one has me stumped, I took a 2 gallon can with me in the hatch, and ran the car out of gas for a second time. pulled the drain plug on the bottom and confirmed it to be empty. Then I put the 2 gallons in and drove to the gas station and it took 5.3 gallons. I could actually see the gas in the neck and the gauge read 1/2 tank. I then ran the car around the block (approx. 6 miles) and back to the pump. It took 2.6 gallons and again I can see fuel in the neck, the gauge now reads between 1/2 and 3/4. So the sender is not hitting the top of the tank. The tank seems to be the correct shape, I didn't drop it but did poke around the top with a coat hanger bent into an "L" shape and couldn't find a depression to turn the "L" down into. So I'm relatively sure it is not crushed. I ran all the vent lines to the evap tank, no kinks or "s" traps. When I pop the fill cap I get no pressure or vaccume sounds. I checked both fuel filters and they are spotless, even after the tank was run completely dry twice. So, By process of elimination I feel that it is in the evap tank. I pulled all the hoses and blew 5 pounds of air through the hoses and the tank itself, no restrictions anywhere. Went to the gas station and with the gauge reading just over half, it took 2.1 gallons, could see fuel in the neck, and the gauge now reads almost 3/4 tank. I am POSITIVE it is not the gauge or sender. The tank must be getting air bound in the venting, or hydrolocked at the baffle. I have not been able to find a baffle configuration diagram in my FSM or on the web. Anyone ever cut a tank up to see what the baffle looks like? The car runs fine, but she just won't swallow.