well Acrylic Enamel wasnt a bad product in its day , from the upper end of the paint manufacturers.

The Catylist ( hardner ) is what made it last, but the isocyinates in the catylist also made it deadly!

If you are just going to use this paint on a trailor with no hardner it might last about 6 months to a year, with hardner and kept polished might go 2 years, longer if garage kept as the UV rays its what breaks down a paint job ! no matter what the the paint is , Lacquer , acrylic uerathane, acrylic enamel, or uerathane .

SprayTech

P.S. When it comes to paint , you usually get what you pay for .