[buffington]

My brother and a cousin both worked at different rental car companies, and I can assure you - they are not well maintained. My cousin worked at Enterprise, and he said they'd buy fleets of cars, run them until they had any failure, then sell them at auction. He was a mechanic, and I remember being gobsmacked when he said "the only fluid I ever put in a vehicle was windshield wiper fluid."

My brother has told me similar stories, though I can't recall specifics at the moment. Most were similar to my cousin's stories, the theme being "as mechanics, we didn't do anything except make sure there was air in tires and wiper fluid."

I think the companies they worked for probably knew what they were doing too. Most cars made within the last 20 years can go a hell of a long way without an oil change and still function (which isn't me saying that "function" means the same thing as "work well long term"). Rental car companies know when to sell them before they stop functioning.