A couple of questions:
What brand of primer do you use? Rattle can? Do you prime everything on the sprues?
No primer. I'm not saying that's necessarily the way to go in every case, but in this particular case, since the parts I want red are already molded in red anyway, I don't see much need for primer.
How did you get the red paint to look so beautiful and perfect on the body and chassis?
Dumb luck mostly. It's just sprayed out of the can. When doing vintage subjects like this, I purposely do NOT try for a flawless, glass-smooth show car finish. Vehicles back then didn't have perfect show car finishes with miles-deep gloss, so my model doesn't, either.
Did I read that you are using Rustoleum in a rattle can?
Yep. A 12 0unce can goes for $4 at my local home center. Compare that to a 3 ounce can of "model paint" at the hobby shop for $7-8. To me it's a no-brainer.
How do you apply the black wash of Future, black craft and water?
Actually I've modified my wash. I don't add water anymore. Adding water was causing the wash to bead and not "lay down" right... so now it's strictly straight Future with a bit of acrylic black. I go by experience... so no real "recipe" I can give you. My guess would be a 15-1 or 20-1 ratio Future to black. Basically I mix up a bit of the wash and apply it. If it looks too "clear" I just add a dab more black... if too black, a few more drops of Future. It's not a hard and fast science. I use a soft watercolor brush and just paint it on. Size of the brush depends on the size of the part I'm applying the wash to.
Sometimes I paint the whole part with the wash (like on the "brass" parts where I want the wash effect and to tone down the part a bit)... sometimes I apply the wash only to the areas where I want it to go (as in highlighting the bolts on the frame rails, for instance). It's all a matter of how I want the finished part to look. The part to get the wash is attached to a bit of scrap sprue (already attached that way for painting purposes, left on the sprue for the wash process.
The real trick with the wash is that it's very thin... not much thicker than water. It tends to pool and run towards "gravity." For example... let's say I want to highlight the molded-in bolts on the chassis rails. I dab a bit of wash on each bolt head... it tends to collect in the crevices, which is exactly what I want it to do. But if I stood the frame rail up vertically while the wash dries (in the position it would be on the finished chassis), the wash would tend to run down and collect at the bottom of each molded-in bolt head, being darker and thicker at the bottom of each bolt head, and not much at all at the top of each bolt head. So in this case I would lay the rail down flat to dry, so the wash stays even around each bolt head. Know what I'm saying? I don't want the natural flow of the wash to be affected by gravity. It's not always possible to "correct" for gravity, though. Another example would be the white hoses. They got an overall wash, but if I left the hose laying flat (horizontally) while the wash dried, the wash would tend to flow down towards the bottom half of the hose and away from the top half. So in that case I stood the hoses on end (vertically) so the wash would stay more constant all the way around the grooves in the hoses.
Sometimes, once the wash is dry, if I find that it's not as dark as I wanted, I just add another coat of wash.
This all sounds harder than it actually is. Once you do a few pieces, you'll get the hang of it without even trying.