I mean this is easy, obvious and right out there but here it is:

My 1989 BMW 525i. It was an E34 made in WEST Germany in 8/88. It had an amber information display that would scroll text along containing various warnings and information. It was insanely useful. I have yet to see a modern car with as useful a source of information regarding the health of your vehicle. The OBDII standard has made things MORE obtuse rather than less. Sure you can plug a tool in, and they’re much cheaper and easier to come by now, but why couldn’t the modern car, with all it’s processing power, simply tell you what’s wrong on one of it’s two or five displays?

This is entirely to make people roll into dealership service departments.

People being ignorant of their own machines contributes, but I say it could also be a chicken and egg thing. If cars *told* you what was wrong rather then simply lighting an SES or Check Engine light, a young driver may be inspired to fix it himself and learn to wrench.

Edit: Fun fact. If I disconnected power on my old E34 it would “forget” it was an NA car for a while and display “Bitte Angurten!” on start-up as well as any other warnings in German. This amnesia seemed to grow worse over the years and as a result I have a surprisingly broad vocabulary of Deutsche car warnings.