I am using PPG products on my 65 convert resto. I have been told they have a GM satin black paint but I do not know what it is. I use their DX685 flattening agent but I am not pleased with it as it is a nuisance to mix/use. I am also looking for a good engine compartment/chassis satin black. Have you looked at the satin black chassis paint advertised by Bill Hirsch? Hirsch