The only spray wax that is really worth it, is meguiars ultimate quik wax. It's good for about 2 weeks, you can apply it to a warm surface in the sunlight, won't stain trim or crevasses. Also good on windows. I wouldn't recommend applying it as you dry. That stuff HATES water; It's basically NXT 2.0 in a spray bottle.
But to get the best protection, do two coats of wax/sealant.
But to get the best protection, do two coats of wax/sealant.