'T.T.' is correct (post #24 above). A car
is seen by many as a status symbol. This has been actively encouraged by HMG and the motor industry since 1963 with the introduction of the year identifier on the registration plate. Remember the queues at midnight on December 31st (later, July 31st) to drive your brand new car out of the dealer's showroom - and the subsequent newspaper reports of the first accident / breakdown.
The type of 'repair' described by 'ITSv40' on an A35 (post #20 above) was prolific on early monocoques. I grew up with such cars and saw it on many others as well as the Austin - typically Ford 100Es and Standard 8s and 10s. Earlier cars, like the 'sit-up-and beg' Ford Pop had a 'proper' chassis' where the condition of the bodywork, not being structural, was much less critical and would need to be flapping in the wind to attract the attention of a passing Police patrol.
Cars of the period often required servicing at 1000 mile intervals, a top overhaul at 10,000 and a full one at 30. Would we accept that today - I don't think so! A selling point was the fitting of a Gold Seal (reconditioned) engine on a used car. Modern mechanics are (generally) much more reliable.
We've already considered corrosion, the subject of this thread, and, I think, would generally agree that cars are much better made today than previously.
Today, I think, the Achilles' Heel of cars is electronics. Heat and vibration are anathema to computers, yet what do we do - drive around with half a dozen under the bonnet! A major electronic failure can render an ageing car beyond economic repair and has spelt the end for many an otherwise serviceable motor-car.
Built-in obsolescence is alive and well!
Regards, John.