You can buy a paint additive called "fish-eye eliminator". Its expensive as Hell, but it does a good job of protecting from the dreaded "fishy-eye". It only takes a few drops to be enough for a whole car---if you have a friend who is a painter, get him to give you an aspirin bottel full of the stuff. Use a "medium dry" reducer---it gives a bit more flow-out time for the paint, and helps eliminate orange peel. Use a charcoal respirator. I have painted a lot of cars outside---do not paint in direct sunlight---put up a tarp sunshade. Do not paint if temp is below 72 degrees F. Paint one very light coat, don't expect much colour build on the first coat. Wait 20 minutes---spray a second coat---you will see the colour start to build, and the tackiness of the now dry first coat will help keep the second coat from running. Wait 20 minutes---Paint a third coat.---Pray----Wash gun with laquer thinners.