Four coats of Auto-Air emerald flake paint have now been applied to the guitar body and have dried. The finish looks really good so far. I've started applying polyurethane as a clear-coat. Each clear-coat application is much thinner (lighter) than I had imagined. I can do a couple of coats per sitting.

Auto-Air instructions mention that any clear-coating helps to bring out the sparkle in the paint, and these thin coats of polyurethane do, but just a little bit. I'm letting each thin coat dry really well, knowing that eventually I'll want to put a thick final coat of clear poly finish on top to really bring out that sparkle effect.