Cat car

Paint it all yellow first-then after it's completely dry-mask and paint the black.

Edit: don't try to spray yellow over black or try to butt 2 colours together-it's best to overlap them.

I hear ya trowlfazz but I'm worried about losing the detail.

Ron

Well Ron-if you use rattle cans it may obscure some detail but I think a bad colour seam is worse-but it's up to you, dude! But either way-spray the yellow first-any black overspray will be hard to cover. You may need to prime first with a light grey primer as yellow is slightly transparent.

If you use laquer instead of enamel you won't loose that much detail as it shrinks quite a lot. Even small scratches show up after using Tamiya's spray cans. I hear that Testors/Modelmaster's new laquer system is good to, we don't get them her in Sweden so this is just what I've heard from others.
Acrylics also tends to shrink a lot but they are a bit on the soft side and not so easy to deal with, very easy to get dents and marks in the paint even after a long drying time.
I have a truck that I tried to polish out one year after I painted it with Tamiya acrylics, it went all soft and felt more lika a chewing gum than paint
So I don't use them very much on bodies.

Good luck!
Niclas

This is going to sound really strange, but paint it white first. Paint the yellow over the whole car then mask for the black.

Without the white, you won't get a really bright yellow. The black will cover the yellow with no colour distortion.

An airbrush is best when it comes to painting but if you have to use a "rattle can", warm the can in warm, NOT boiling water for 5 minutes and it will flow smoother on the car. Use light coats allowing to dry in between otherwise it may run and that's not good.

Wait until the white has really dried before painting the yellow and allow a week before masking.

If you are concerned about the black bleeding under the tape on to the yellow, spray yellow where the black is going to go, allow to dry then spray the black. If there is any bleeding, it's the yellow not the black that bleeds through.

You can also reduce or eliminate the bleeding under the tape with a clear coat before the black. You can also spray the yellow areas with a little yellow in the areas that will be black. This way you do not have an "extra" coat of yellow in the "black" areas other than an 1/8 inch or so into the black area. Also, try not to spray "into" the edge of the tape. Spray from behind the tape edge and at something less than 90 degrees to the tape edge (wherever possible).
As another suggestion, pull the tape before the black gets "tacky". If it is still "wet" it will "lay down" if there is no tape edge to hold up the black edge. The generally means spraying the black in sections, unless you are quick. Just some thoughts.