Good point Wha Who. Cars with good bodies and good, simple mechanicals can be fixed economically for a very long time. As you say, you also have to like the car well enough to keep doing that.
Having said that, some cars reach a point of no return quicker, where very expensive repairs are needed to keep them running, and owners decide to scrap the car. Some Volvos, Land Rovers, Jaguars, Audis come to mind. Others are orphan cars for which parts may no longer be available. I have yet to see a very high mileage Jaguar, for instance.
Examples of vehicles that can be repaired economically for a very long time are full size 2 WD US pickup trucks, compact Japanese cars, US cars such as the Crown Victoria, Ford Taurus,and others for which parts are economically available for a long time and the car is basically simple, reliable, and have a designed-in lifespan that allows this continuous fixing.
The longest mileage vehicle I ever rode in was a Toyota Corolla diesel taxi in Asia with 1.4 million kilometers (870,000 miles) on it. I could not imagine this to be a Fiat, Renault or other make with lower design standards.
My statements are not in conflict with other posters; some cars just have better "genes’ than others, and the production volume and spares availability and prices (especially after-market)usually determine how long a vehicle will live.
We get many posts about very high mileage Ford Taurus cars, pickup trucks, large rear drive cars, most of which are not in the “much better than average” reliability rating in Consumer Reports.
Much of my work deals with equipment life cycle costing and when to decommission the equipment or justify a further “life extension” repair. The intrinsic reliability as well as the cost of any repair weighs heavily in these decisions. Taxi companies tend to have the most experience in wringing the last ounce of life out of a machine. They invariably pick simple machines that are easy and cheap to fix. For them it will be a sad day when the Crown Victoria will be phased out.