Vinyl is imperfect, being used because nothing else is better. Being inherently soft-surfaced, it scratches readily and easily absorbs a wide range of chemistries from water, acids and all manner of hydrocarbons. Clear �plastic� windows in soft-topped cars tend to cloud slightly when humidified and it gets coloured by industrial fallout and most cleaning agents. It is optically transparent to UV, and while it is relatively stable against UV-cross linking itself, it can absorb all the other stuff. Clouding back window clear vinyl can be vastly improved with Magic Rear Vinyl Window Renovator.

Plasticizers, an oil-like hydrocarbon, make vinyl dashes, linings flexible. Vinyl is a sparse matrix of plastic sponge which is indulged in liquid plasticizers. High percentages of plasticizer potentiates contamination by airborne stuff. The plasticizer quickly dissolves the junk from the surface, spreading it throughout the material.

Automotive vinyl is usually made with very good plasticizers to minimize evaporation & therefore, stability. Evaporative stability and good low-temperature flexibility are difficult to achieve together. Plasticizers are readily stripped from the surface of vinyl by anything that can bind and lift oils, including detergents and soaps, but not with PH neutral MAGIC WASH.

Especially evident in new cars, the film that forms on the inside of the glass consists of condensed plasticizers that heat-evaporated from the back window, the dash, the linings, and from some types of leather seats.

Strong cleaners, some with ammonia, will strip more and more plasticizers. When cleaning loss is combined with gradual evaporative loss, the vinyl becomes less well plasticized, and thus stiffer. Decreased plasticizer content, varying temperatures, and stiffening due to UV-cross linking can all lead to cracking.

The best option for auto maintenance are to strictly avoid exposing the vinyl to even trace amounts of anything not water .