[Caymanboy]

No, or sorta no, guide coat is basically flat black laquer in a spray can, you spray it on (lightly, hence guide coat), then when you sand, you can a) see where you have been, b) see all the imperfections. You want two coats of primer, you should be able to go over the first coat an hour you have finished.
You want all (or as many of the imperfections filled before the primer application.