[theastronaut]

Single stage metallic isn't very forgiving. You have to get each coat wet enough to flow out to minimize orange peel, yet dry enough so the metallic particles don't sag. And you have to do this over every square inch of the car. If you're doing an all-over then you have to do it quickly enough to get back around to where you started so there's not a dry edge. Then you have to do that for each coat.

I'd suggest stopping where you're at, blocking it down with 220 then 600, and shooting it again with base clear. If you plan on wetsanding and buffing it then you'll have better results with clear, otherwise you'll be cutting into the metallic particles when you wetsand and buff.