You may recall also that car manufacturers - especially the domestic automakers - would create new body styles each year so that it was easy to tell (at the time and even today, decades later) a 1956 model from a 1955 styling or a 1963 from a 1960, for instance.
Then, along the way, cars started looking more alike - from year-to-year and across brands. It became more difficult to distinguish who the manufacturer was or the specific model of the car for many of the cars on the road. Every so many years, car makers would have a body redesign where they would change things up, but until that happened, it was hard - except for the most discerning eye - to recognize which year and which make was being driven down the road.
That led to people keeping their cars longer - that and a few other things, such as people financing their cars for up to seven years (it had been three, then four, and then five, on its way to seven in some cases), cars being made from aluminum instead of steel so they didn't rust, better maintenance programs and warranties, and people enjoying not having to make a car payment every month.
Unless a person knows for sure what body styling changes have occurred from year-to-year or every few years with the car they drive or like, it's likely that 10-15 year-old cars are driving up and down the roads all around us without us even giving it a second thought.
This is where the parallel to aging-in-place occurs. Some people purchase a car - new from the dealer or in very good condition from a private owner or a dealer that specializes in quality used vehicles - and they like it. They don't necessarily plan on keeping it for any specified period of time, but they really like the way it drives, the storage capacity, the gas mileage, the styling, and other qualities about it. The years pass, it is paid off, and they still drive it - with no immediate thoughts of replacing it. They have sort-of aged-in-place with their car.
Other people shop for and select a car - principally a new one from a dealer, but not always - with the idea that they will keep it for a minimum of 10 years. Therefore, they are much more careful in doing their homework, investigating the performance characteristics of it, and making relatively sure that they will be happy driving it for the next decade or even longer. They pick a color, styling, and interior features that they feel will have the best chance of keeping up with the passing years.
Of course, as people need to - just as with their homes - they can add features to augment their general comfort and safety - more lighting, better mirrors, electronic systems, different seats, and more.
While we like to focus - with good reason - on aging-in-place in our homes, many of us are following a similar pattern with our vehicles.