My The so called Auto paint is just a realative term depending on the year and make of car if you are talking Factory paint. Most modern Factory base/clear coat has been highly regulated by the Gov. for clear air act, low VOC paint, water based and in the beginning dissaster and evan today not as forgiving to the elements that a lot of people think, 1997 PLY. voyager after year 8 hood and roof totally trashed. On 78 volare shop repaint with single stage acrylic after year 5 highly faded and rust was back. 1988 Olds factory paint has ZERO clear left on all Horizontal surfaces and as smooth as concrete but I do not have the time frame on deteroation. Just look around next time your are driving around town all the factory auto paint that is faded, peeling, chipping, or covered by orage peel. Most purest Hot rodders will only use laquer paint for its high gloss but to get it ... you guessed right color sand, then polish, then wax, it is never used by auto makers any more today... labour intensive and not very durable to the elements. Alkayd enamal has been used by Auto industry in the past. Up to a point most factory paint is designed to last 5 years ... The pay of date for most of us poor debt laiden fools. Since car prices have gone up over the last several years I geuss it is resonable to assume the life expectency of the factory paint to at least match it. I also have fond memories of an Old 1960 something blue ford pickup with original paint that would chalk out and about once a year, help dad wax it up and the deep, smooth, gloss blue would return again.