over to 24 volt systems back in 1978. The goal was to save weight and to simplify their avionics systems between single-engines planes and light twins which had used 24 volt systems for years.

All it did was really piss off the owners. Suddenly, even simple things like light bulbs for the instrument panel became much more expensive. You couldn't use the aviation equavilent of automotive parts anymore. For example, a 12 volt alternator for an older Cessna might cost $40 while a 24 volt alternator, being a limited production item, might cost hundreds. Aircraft batteries aren't cheap (hell, nothing on planes is cheap) but try buying a 24 volt battery. They easily cost twice as much as 12 volt batteries with no higher energy ratings. The 12 volt lights last longer, too, for the reason given in the article. I'm glad my Cessna was built in 1975.

I suspect the problem will be the same for cars for at least a few years until production can ramp up on 42 volt systems. Just like the price differential isn't as great between 12v and 24v aircraft systems any more, in time prices will become more reasonable for 42 volt auto systems.