Truthfully I think anything over two coats in a waste. A lot of times people think layering a wax will create more of a shine. It will not It won't add protection either. Now then is no reason to layer a a sealent. Waxes and seleants only amplify whats underneath it while adding protection. The only reason you should layer a carnuba or sealent is to make sure every area of the surface is covered. other then that its a waste., now back to your ? Two thin coats to ensure maximum coverage.