debris. The disadvantage of using a petroleum-based coating is the film left over on surfaces, rendering these products too messy for top side exterior application, and unsafe in areas where it can be slipped on. They also cannot be painted. There are aftermarket electronic "rustproofing" technologies claimed to prevent corrosion by "pushing" electrons into the car body, to limit the combination of oxygen and iron to form rust. The loss of electrons in paint is also claimed to be the cause of “paint oxidisation” and the electronic system is also supposed to protect the paint. However, there is no peer reviewed scientific testing and validation supporting the use of these devices and corrosion control professionals find they do not work. Rate of corrosion The rate at which vehicles corrode is dependent upon: Local climate and use of ice-melting chemicals (salt) upon the roads Atmospheric pollution, such as acid rain or salt spray, which can cause paint damage Quality, thickness, and composition of metal used, often an alloy of mild steel Improper use of some dissimilar metals, which can accelerate the rusting of steel bodywork through electrolytic corrosion Design of "rust traps" (nooks and crannies that collect road dirt and water) Particular process of rustproofing used Plastic/under-seal protection on the car underside Exposure to salt water, which strips off the protective paint and also causes rust much more quickly than ordinary rain water would Rustproof alloys Stainless steel, also known as "inox steel" does not stain, corrode, or rust as easily as ordinary steel. Pierre Berthier, a Frenchman, was the first to notice the rust-resistant properties of mixing chromium with alloys in 1821, which led to new metal treating and metallurgy processes, and eventually the creation of usable stainless steel. DeLorean cars had a fiberglass body structure with a steel backbone chassis, along with external brushed stainless-steel body panels. Some cars have been made from aluminum, which may be more corrosion resistant than steel when exposed to water, but not to salt or certain other chemicals. See also Corrosion Corrosion engineering Hot-dip galvanizing Tinning Iron pillar of Delhi Cathodic Protection for Vehicles Cosmoline Corrosion inhibitor References Vehicle technology Corrosion prevention Materials science