This may or may not be a simple answer. Ive only painted a full car once and it was a my 69' Blazer which I dont own anymore. But those have full convert. tops so I never painted the roof. How is the roof of the car painted even? It seems like you would have to stop when you get half way across then move to the other side of the car and continue? It seems like it would have an uneven line between there? Im picturing it being tricky! :confused:

I'm sure there are many techniques out there but here's what works best for me. Start atone end of the car, I usually start with the rear. Start applying paint to the lower side of one quarter working your way up and across to the middle of the decklid, then come around the back of the car's rear panel and from the center of the decklid down the other quarter, then jump to the center section of the car from the bottom of the left rocker, up the door and over the roof half way, switch sides and finish from the middle of the roof and go down the right door to the bottom of the right rocker, switch sides and from the bottom of the left fender go up and half way across the hood, come around the front then finish from the center of the hood and down the right fender. Apply until full color coverage is obtained usually 2-3 coats then if a metalic 2-3 drop coats walking the length of the car.
If it's a candy being sprayed you'll need to walk the entire length of the car for all with no stopping midpanel.
The object is to apply the paint so all melts together, example-if you started in the middle of the hood then worked your way down one side of the car then came back to the hood center from the other side the paint you applied to the first side of the hood would be to dry.
Keep in mind where you are stopping the gun midpanel and stop in a different spot on the next coat. Usually where the gun stops there will be an additional amount of paint from overlap and if it happens in the same area for all coats you may get a sag or metalic mottling. Example, if you stop the gun at the door to quarter opening on the first coat then stop say 20 inches into the door on the next coat then 20 inches before the door on the following coat etc.,
Base coat is very forgiving, clearcoat will have dry spots or runs if attention isn't paid to the way it's applied.
Hope I helped, if someone has a better technique chime in, we're all here to help and learn. Bob

Like badbob said....there are many techniques...
A lot depends on the type of spray booth.
In a Down draft booth, you never work from the bottom up. In a cross draft booth, it's best to work from the intake end, to the exhaust end.
This keeps the overspray from landing on the wet paint.
The object is to keep a "wet edge"
Personally, I start with the roof...if you start with the deck lid, and quarter, etc., by the time you get to the roof, you're blowing overspray on the decklid, quarter, or whatever else you've already sprayed. (especially in a down draft booth)
Start on one side of the roof, working from the outside towards the center. Go as far as you can reach without dragging the gun in the paint.
Then move to the other side, and finish up from the center to the outside edge. From there, it's all up to the painter. Some guys jump from side, to side, some go up one side, over the hood, and down the other....it just depends on the painter.
After you do a few paint jobs, you just learn what works best for you.
Ask 10 painters this same question, and you'll get 10 different answers.