There was a really cool artical in hot rod,a bout painting a car with enamel paint, and sponge applicators.

I think they did a falcon or something, and it turned out great.

That is my plan for my fargo, as it is under $100 too.

As for actually painting a car with a spray gun at home, I think keeping it clean is a must, but the make or break will be how good you are with the gun.
You have to be quite confident that the earlier coats are tacky, when you throw on the thick final coat to shine it up. If not, it run's all over.

For lack of a better term, you need to have big kahuna's to get it done well.