Let me throw something out here. I have painted 2 cars with acrylic enamel with a urethane catalyst. The first was a 47 Ford conv in 1975. I painted it with Sherwin Williams acrylic enamel with Polysol. It was brand new technology then. Everyone tried to talk me out of it but I did it anyway. Back then the other choice was lacquer. I did cut and buff the acrylic enamel and almost 40 years later the car is still on the road and looking pretty good. The second was a black Malibu that I had a buddy paint with PPG's Starthane. It also was cut and buffed and was beautiful.......for about 4 years. After that the paint began to die. the 47 ford has always been a garage kept car. The Malibu was my wife's driver and lived in the sun all day at work. Of course that black paint got really hot out there in the sun. I know you can do some really pretty work with the catalyzed enamels but you may want to consider the environment the car will live in after it is painted.