Rarely happens though in practice with ICE cars, average age of a car being scrapped in the UK is about 13 years, average age on the road is about 8 years. Car lifespan has been increasing in Western Europe as car reliability has improved. In general Cars do not rust as quickly as they used to, obviously there will be individual Friday afternoon shit boxes or even entire ranges as with Merc between the 90s and early 2000s. But in general they are light years better than pre 2000s and especially pre 1980s when they could start rusting their first year.

In practice the cost to repair vs. value of the car tends to dictate its lifespan in Europe, it becomes cheaper to replace the car than fix it. This is the cycle we need to end.

Current it tends to be limited to enthusiasts to upgrade the capabilities of ICE cars such as more powerful or efficient engine, etc. I do not see this market changing with EVs, you can already by performance upgrades for Teslas for example, even if I wouldn't touch these 3rd party performance upgrades with a ten foot pole (outside of things like brakes and suspension).

Retrofitting a much more efficient engine to a modern ICE car is difficult, it requires all sorts of other upgrades to enable it and manufacturers have been busy trying to lock people out, see BMW and their ECU encryption. Retrofitting a larger battery, particularly to earlier cars is reasonably trivial in comparison and the old battery still has value, whereas a knackered gearbox/engine/ecu combo is worth considerably less for the average car.

This should be similar to a right to repair law for EVs that also enables them to take advantage of the latest tech.