We are using this primer called slick sand, it is a primer with liquid bondo in it. It lays on thick and you block it down so its nice and smooth and straight. It will fill in sanding scratches but you wont get away with murder with it. The body guy that comes over my house every saturday uses a hvlp gun and we are only spraying the primer outside in my drive way. When we lay down the color and clear we are bringing it to the guys shop and using a professional spray booth. I think the final coat of primer (not slick sand) we are also spraying in the drive way. About the shade canopy we are in south Florida and the humidity is kiling us. It helps to block the sun but you are still dripping with sweat just walking outside. we just bought it and it was a great deal at Walmart for like 85 bucks.