Car companies choose what is simple to manufacture, but eventually making it very hard to maintain. If it where not for regulation, they would give you something that has a timer for breaking. That is how little they respect their customers.
Anecdotal (but at this point one of hundreds I've come across): older car had fuel pump accessible through a little sealed hatch. In current car the same pump was integrated into the fuel tank. It went bad. Guess what? You have to remove the whole fuel tank to service it. And that entails taking the exhaust out of the way. Car companies hate you.
Sidenote: this one of the ideas behind Ida Aukens (controversial, and I would say misunderstood) "You will own nothing and be happy": One way to make companies liable is by making them own and maintain what they produce for the entire product cycle, and you only rent these items.
Of course this needs a very healthy and competitive market with effective regulations to prevent eternal enshittification. And maybe it doesn't work when shareholder value is everything that counts.
The most idiotic thing I've had to deal with so far was headlight replacement on a Subaru Outback. On the driver's side, you can't get to the headlight from the top. You have to take out the whole front wheel well liner, remove some other things, and then you can GET to the headlight, but it's way back there and you can't even SEE it. So you have to do the job blind and one-handed. I did it ONCE and hated every second of it.
On the automotive scale, rust is a solved issue.
Nickle dip, electro deposition coatings, powder coating, salt spray testing, limited exposed welds.
GP is incorrect. Rust is not the issue for avoiding steel.
It is weight. Period. Every group at every mfg is given a weight reduction goal per model line and refresh. Vehicle network systems had a bullet point not of safer, or easier, or redundant, which it is none of those things - but low weight as you can cut a lot of copper out.
The old '61 Mack truck I have is just plain sheet metal and has a lot of rust holes in the cab and body work. My 2001 Pathfinder had a failed strut tower in 2013 from the sheet metal rusting out (well known issue Nissan screwed people with.) Newer Chevy's and so on seem to hold up decently and I hope my '22 CR-V lasts 20 years.
The issue with steel is weight, end of story. All alloys are constantly getting application specific versions and changes. TFA is basically worthless.
I don't quite follow this logic? I am talking about what happens to cars with steel frames after a decade. Of course new cars aren't rusting out, but a large percentage of the ones made in 2009-2024 most certainly are. In the midwest/northeast US at least.
2) where I come from, in cca eastern Europe with cca harsher winters, all sane folks who value their cars get right after buying get some additional protective layer on the bottom of the car (don't know details, don't live there but its not a trivial process). Easily lasts a decade. Back home during winter there is often salt and other chemistry used on the roads so without that, it would be bad much quicker.
If you live next to sea/ocean, you are screwed though I think, salt in the air corrodes almost everything.
Europe is a big place. You'd be surprised how easy it is to bribe the safety inspectors in some countries.