I would like to point out that you guys should really focus on the clear coating. Remember, these are on the front of your cars, so they will see debris in various sort.
In a two stage paint (basecoat/clearcoat) process, the base coat is for color only, the clear is what will supply the gloss and protection. It is to be sprayed until it is uniformly coated, but don't go overboard.... you can only have a certian MIL thickness of primer, base and clear in the end and still have a durable product. Spray too much and it'll take a bit longer to fully cure and easier to chip in the long run. I would also spray a let down panel, so you know how many coats of base coat it'll take to match your existing paint.
I try to spray as little primer and base coat to allow the bulk of the total amount sprayed to be clear coat. That way you can spray more clear for added depth and ability to cut and buff it to an absolute mirror.
I painted my eyebrows on my headlight lense. After "cutting and buffing", you can't even feel where the paint starts and the paint ends