Thanks for the reply.
I found this picture of the xB fuel tank.
The tank has quite an irregular shape, so maybe there could remain some air pockets once the fuel level has reached the height of the filler tube connection to the tank. Then any further filling requires the head caused by repetively filling the filler tube. The tank's breather may be affected? Then the slow flowing head of fuel in the filler tube triggers the gas station's pump to cut off. Just a guess. May be inherent in the design.
Or maybe the dealer applied thick rust proofing gunk is constricting my tank's breather and vents? Just another guess...
It must be a different shape tank on your tC?
I still wonder if any 2011 xB's don't have this problem. Winter's coming! And I want to make fill ups quick!