A friend of mine worked as a Ford mechanic in Texas in the 80s. They had an infamous customer who drove an LTD with cloth interior. Apparently this Good Old Boy(tm) would throw his fast food detritus in the back seat, and only clean it out when the pile got high enough for them to spill over back in to the front seat. But that wasn’t the worst, he did chew and would apparently spit the chew at/on the dashboard.

So you had a car with rotting food bits in the back seat, and old spit & chew encrusted on the dash (to the point where my friend would have to scrape it off to see the dash warning lights). All baking in the Texas heat all day.