A standard feature of the car wash is the wax arch. The wax that is used in a car wash, which forms a water-resistant coating, is quite different from the wax you would apply by hand. One of the key differences is that car-wash wax is formulated to work on glass, chrome and rubber, as well as the painted plastic and metal surfaces of the car. Also, it leaves a clear, thin film that does not have to be polished first. However, car-wash wax does not provide the same level of protection, nor help to remove or cover up tiny scratches, as standard wax does.
The wax arch uses one of two methods to apply wax. The first type of wax arch uses a system of foam applicators, the most common being a triple-foam applicator, to apply a foam wax.
The second type uses nozzles, similar to those of the rinse arch, to apply a liquid wax. In this case, the next step is usually to go through a rinse arch. But when wax foam has been applied, the car usually goes through another set of scrubbers and another mitter curtain before going through a rinse arch.