I have had the California nozzle problem twice! In my case ( 2005 Dolphin 5320 ) the nozzle got stuck, and the attendant had to remove the nozzle boot to get it out. I checked the configuration of my fuel filler, comparing it with the ones on my Jeep & the Wife's SUV. Both of the passenger cars had filler necks with the fuel port in the center. The Dolphin, however had the port offset ( off center ) toward the bottom of the fixture. It also appeared that the RV neck had an auxilliary port toward the top, the probably leads to a pipe, & thence to a vapor cannister. A check of California regulations indicated the requirement of such a cannister for fuel tanks larger than 50 gallons. These 'observations" however, do nothing to solve the problem! I will check out the winnie link, above, to see if that "fix" complies with Cal-regs.
2005 Dolphin 5320