Spray wax at a car wash does provide a little protection for the paint and adds a bit of a shine. It also tends to rejuvenate any remaining wax. The downside of spray wax is that you are also applying wax to the windows.

Most professional detailers use some type of carnauba paste wax. However, applying paste-style carnauba waxes can sometimes require more elbow grease than liquid or spray waxes. Many at-home detailers find that they get a satisfactory shine and protection from easier-to-apply spray or liquid waxes.