^^i took this from their help page...
"Note: Not recommended with vapor hooded nozzles. On hooded nozzles you may need to hold the nozzle in position to refuel properly or remove the cap and refuel without using the InStant Fill cap.
Note: If you are having difficulty, you may remove the cap and refuel without using the InStant cap.
Warning: Do not spray this cap directly with a stream of water. This may allow water to enter the fuel system.
Questions? 1-800-822-3121."
didnt say anything about state usage...i would call the 1-800 number and ask them...
Stant