The Technical University of Munich has carried out an impartial scientific comparison test in association with Mercedes-Benz to establish the exact ranking of hand washing versus machine washing of vehicles relative to damage to paintwork.

The International Carwash Association working through a special Carwash Research Foundation Grant to the University of Texas at Arlington, Texas, has conducted extensive car washing tests this past year to determine the effect on car finishes by comparing various car washing techniques ranging from professional car washing to the bucket and sponge used by many auto owners.