RE: Polycrylic and Polyurethane
A while back, I did a test with both Polycrylic and standard oil-based Minwax poly. I let each dry in the sun for over a week, placed a small puddle of Cool Power 15% on each for an hour, then wiped it off. The oil-based wasn't even phased by the fuel, but the Polycrylic was soft and sticky and never hardened again after that. Though this is in California, so maybe the formulations are different here because of the strict environmental laws.
I have also used flat black spray paint from Sears (their own brand) that is fuel proof to 15% - not bothered by raw fuel. But not sure about the other colors in their line of paint - might be worth a try for a top-coat.