Back in the day you could buy whole (but small) parts, cut away the rusy one and solder in the new one (paint with anti rust paint). Did it on my cheap ass volvo 142 :-)
Maybe you can't do that any more because of complex crumple zones, but I bet we can do better. A car shouldn't just have a life span of 6-10 years.
A car shouldn't just have a life span of 6-10 years.
They don't.
My current daily driver is 18 years old. I expect at least another 10 barring an accident, maybe 30 more years as a spare vehicle. It got a new transmission at 200,000 miles. Engine seems like it'll make it to at least 400k. A replacement is $1500, far less than a new car.
Most cars in my family (approximately 30 cars) are between ten and thirty years old.
I've had 3 cars since 1996, all bought used, and I traveled for work with one. One car I sold to a family member, and it's still being driven.
It's people that choose to not drive cars this long.
Same. We're at 17 and 18 years, and we're looking for replacements because we want something more efficient. We'll probably sell them instead of junking them. We bought one at ~8yo, and the other at ~15yo, each has had minimal issues and I've done most of the work on them myself. Neither have any rust, though we live in a desert, so that's not all that surprised.
Cars absolutely can last quite a while if they're well maintained and designed well.
You can still do that. They're called body repair panels. They are usually plain metal. You have to cut out the old, weld in the new, grind them flat, prime and paint them. This isn't cost efficient if your car is worth less than the paint you'd need. The parts usually are around $100-$300 bucks (if you don't need OEM parts) but the labor is expensive. And if you do it for cheap it will look like crap.