Without having to "scuff the clear" to pinstripe, I take it that you're finished upon removing the stencil or when finished free handing. That's excellent news knowing that three more coats of clear are not needed over the pin striping.
If using a stencil, do you wait until the striping paint is dry (to remove stencil), or do you remove the stencil when the paint is "green"?
Any problems with buffing, without clear over the pinstripe?