FILL TRIM HOLES
They say you shouldn't fill trim holes with body filler because it will shrink and pop out, but in our experience, the newer fiberglass-reinforced fillers will hold tight in an 11/48-inch hole virtually forever. If you're a novice, it's better than warping the panel with a welder and a grinder. Just fill small holes with Everglass (or similar), then sand with 80-grit, smooth with body glaze, and finally smooth it all with 180-grit.
SAND TILL YOU BLEED
Once the car is as disassembled as it gets and all the dents you can fix are repaired, sand forever with 180-grit, which is as fine as you want to go for the primer to stick well. The photo shows us at 5:30 a.m. after we'd been rubbing on the car for 12-plus hours. And we could have used more. The more you're willing to sand, the straighter the car will be and the fewer flaws you'll find. Use longboards on big surfaces and Popsicle sticks to get into the tiny crevices. Body glaze may be needed on areas where you sand through to bare metal, especially if the car has a lot of old paint jobs on it.
MARK THE DENTS YOU NEED REPAIRED
When you're done, there are likely to be some dents that you don't want to tackle. If you want the shop to fix a dent, make sure to mark it with a pen (or better, with masking tape), then take a picture to document the dent (to prove that you asked for it to be fixed in case they don't do it). Production shops will only fix dents that are specifically requested to be fixed, and you'll pay an hourly rate for them to do it.
WASH IT FOREVER
When all the sanding is done, blow off the car with compressed air if you've got it, focusing on all the little crevices. Next, wash it for as long as you can, cleaning everything and then blowing it out again with air. However, make sure not to use car-wash soap, which usually contains silicone for shine. In fact, the longer you can keep silicone products off the car before it gets painted the better. Do all your scrubbing with dish soap.
MASK CRITICAL PARTS YOURSELF
If there's anything you really, really want to keep paint off of, mask it yourself. This window felt is a good example of something that is a pain to change but looks terrible if it gets color on it. Pull it back with the masking tape as far as you can to avoid old color showing at the masked edge. Masking your engine is also a good idea, since it's bound to get fogged in overspray.
REMOVE WAX AND GREASE
While the car will certainly get handled quite a bit before it goes in the booth, we figure the best chance to reduce fisheyes in the paint is to degrease the surfaces as much as you can yourself. It will get done again at the shop, but why not be thorough?
SEND IT WITH TIRES YOU HATE
There's no chance you'll escape the paint shop without at least some overspray on your tires and wheels. Bolt on some throwaways before you take the car in to be painted.
PICK THE RIGHT COLOR
When you're going for cheap paint, your budget and your bodywork partially dictate the color. We took heavy advice from John Chohlis at the 1 Day Paint & Body in Torrance, California, where we took the Nova. A repaint of the same color is always safe, since chips will show less than if you, for example, painted a yellow car black. You can also choose a color of the same general tone as the base paint for the same reason. If your bodywork is really bad, then white and bright yellow are always safe bets, since they reflect the most light. Dark colors are the worst when it comes to revealing body flaws, and we think metallics can look bad if you don't step up to a basecoat/clearcoat process. We ultimately chose '04 Ford Zinc Yellow, partially to hide our mediocre dent repair, partially so it would be easy to buy touch-up paint, and partially in tribute to the long-lost Car Craft Cheap Street Chevelle. We had the car sprayed with regular single-stage paint but added a clearcoat so we could color-sand it later. A true basecoat/clearcoat system would have cost much more.
BLACK OUT THE OVERSPRAY
When your project comes home there's bound to be overspray all over the inner fenderwells and on the undercarriage. Ours was not nearly as bad as expected, and the shop had blackened out behind the grille for us. We still spent a few cans of VHT semigloss black to kill the misplaced yellow.