I'm not familiar with spraymax 2 part paint, but the issue is usually UV resistance. Paint will typically fade if it isn't coated with a UV resistant clear. Having a clear coat also helps protect the paint from scuffs and nicks.
If I recall correctly, I may have used spraymax paint before, but it was not a two part paint, so it would not be gas resistant. The two part paint systems from spraymax have a button to punch on the bottom of the can that releases the hardener. Without that button, you won't have a fuel resistant paint.
Be careful when you use that stuff. Get the appropriate mask to filter out organic matter. Otherwise you could end up in the hospital, with cancer or nervous system disorders down the road, lose testicle function, etc. The various chemicals can penetrate your skin too, but a long sleeve work shirt will probably limit that exposure.
Camelman