Any warranty which isn't transferable isn't very valuable as the vast majority of buyers do not keep a car 10 years or even 7. 3 or 4 or less is the norm these days. For used cars the average is about 2 years.

Cars tend to be designed around an approx 10 years life and the average age of scrapping is 13 years in the UK.

Most cars are scrapped because they've become uneconomic to repair or maintain, not because they're worn out. As cars have become more reliable and long-lived, they've also become more complex so a single fault could cost more than the car's value.

Technically you could keep any car going for ever if you wanted to and wanted to keep spending unlimited money. Cars are built down to a price though and not designed to last forever.

If something need repairing and it is expensive to replace then it is worn out. The motivation to keep spending big on a 15 year old car which may well have another expensive failure just isn't there. On top of that cars simply date and drivers want something newer and more modern and that's before we get to environmental issues which means in some parts of the country owners will be dumping older cars simply because it is not viable to own then where they live.

<< Most cars are scrapped because they've become uneconomic to repair or maintain, not because they're worn out. >>

This well established piece of irrationality has been discussed here ad nauseam. Comparing a cost of repair with the presumed market value of a car is very easy, but silly. A repair is done to restore market value so that the car can be sold instead of scrapped. A more likely reason for scrapping is just a wish for something newer.

I suspect that a 'norm' of 3 or 4 years may have something to do with the typical length of warranty, and owners moving on before it expires.

Any warranty which isn't transferable isn't very valuable as the vast majority of buyers do not keep a car 10 years or even 7. 3 or 4 or less is the norm these days. For used cars the average is about 2 years.

Cars tend to be designed around an approx 10 years life and the average age of scrapping is 13 years in the UK.

Most cars are scrapped because they've become uneconomic to repair or maintain, not because they're worn out. As cars have become more reliable and long-lived, they've also become more complex so a single fault could cost more than the car's value.

That's often because the latest owners rarely bother to budget for repairs other than the odd tyre, indie servicing and windscreen wiper replacement, and buy such cars often because of the brand/model/looks.performance, not seeing that it could make the car in effect a write-off the minute some more expensive-to-replace wear and tear part needs replacing soon or has a known reliability issue.

This is especially true of people purchasing second hand so-called premium cars, especially German branded ones.

A former (young) colleague of mine bought a 5+ yo BMW 3 series, scrimped on the servicing, ignored oil leaks, which resulted in it depositing the entire engine's contents on his driveway (thought he didn't notice before starting the car), ruining the drive and his engine in the process.

The car was scrapped as he had to spend the money on relaying the drive and shelling out for a cheaper bog-standard replacement car. If people can't afford to run a premium car when it's new, they definitely can't when it's several years older.