Well, in the '60s, manufacturers were touting how low their maintenance costs were compared to the other guys. If you didn't have to grease your chassis, your cost was lower. Extended oil & filter changes were also incorporated at that time. Cars required a lot of attention with tune-ups, tires that were wore out in 5000 miles & so on. Maintenance cost were a big deal for fleets like Hertz & Avis. I don't think it was cost as much as it was bragging rights.