I'm thinking an alternative would be to take a piece of transparency, like the kind used for an overhead projector, and use a paper hole puncher to punch out holes across it. Then, you can lay this across large flat parts of the body as a stencil. You just need to make sure the paint isn't too wet, or it might seep under the stencil. I used this material to stencil spraypaint on a model kit before. As for the sides/curved parts, you can use the same thing, but you probably should make a new stencil with less holes and hold it in place while spraying or similar.