Definition (Source: Wikipedia)
***A car wash is a facility used to clean the exterior, and the interior, of automobiles. While there are many different types of car washes, most fall into three main groups:
Self-service facilities, that are generally coin-operated
In-Bay Automatics, which consist of an automatic machine that rolls back and forth over a stationary vehicle while washing it
"Tunnel washes", which use conveyors to push or pull the vehicle through a series of fixed cleaning mechanisms.
Mechanized car washes, especially those with brushes, were once avoided by some meticulous car owners because of the risk of damaging the finish. This perception of vehicle damage was the motivation behind the rise of the touch-free car wash facility. Touch-free car washing, however, proved to be an extremely difficult endeavor with many types of touch-free machines and extremely harsh, even dangerous chemicals that are used in order to get a vehicle clean. Many of these chemicals have the potential to cause more damage than the brush type washes they replaced. Today, buffered chemicals, improved hydro-dynamic cleaning systems and modern foam based materials for friction washes have greatly reduced the chance of vehicle damage in car wash facilities.