Oh alright thanks! (and thanks Scott)

I didn't know that about the primer surface. I'd seen cars rattle can painted without sanding the primer before, so I wasn't sure how much it mattered. Granted, the cars were stock ice racers so the paint job didn't matter too much and didn't have to last very long. But yeah if I'm going to go through this painting process I'll definitely take one more step and sand between primer and paint too. I got tired of reading after about 50 pages of posts (starting in first thread) and then started jumping around and skimming and looking at people's before and after pics... so I didn't see Marq's explanation, thanks for the tip.

Bummer about the hood rusting through, but I guess it's better to happen now than later on after you've got a nice complete paintjob on the whole truck. Good luck finishing your project. It's funny, with "rust" in their name, shouldn't all Rustoleum paints have better-than-average rust blocking properties? lol.