If he ever drove anything from the Leyland group I can understand wanting to replace every 3-4 years.
But that's an issue from another time; modern cars do not need replacing at that age.
(although keep a note on the JD Power and similar surveys to know wihch to avoid).
He could also h\ve saved a fortune by not buying new every time.
Nearly new is a great option.
I did say!
I have always bought cars about 2-4 years old and had fewer problem than he had buying new
In his case it was his disability that made him buy new
The apparent safety from problems made him feel safer in case of a breakdown or failure - he was pretty much stuck in the house if teh car failed
note the "apparent" part of the above sentence
I can remember
a Capri (Mark1) that had so many suspension problems that it ended going back to the factory to find out when was wrong
Maestro that had so many faults that listing them would take too long - engine was mostly OK but then my Unclde (a motor mechanic) said it was basically a bigger version of a Morris Minor engine - including the other engine gubbins!!
A Rover 213 (Honda colaboration ) that was mostly OK but the seat fabric had to be replaced after 3 months
A Rover 216 where the big-end went in under 1000 miles!
Notice that I didn;t include the Cortina Mk1 Capri Mk(the last) or the 2 Renaults in there - as they never went wrong
He wanted to 'buy British' and gave up in the end when he got a Honda and just decided any car with 'Made in Britain" on it was to be avoided
Funnily enough - many years later he got to know a bloke who knew more about Steel that most engineers - he was incharge (in some way) of all the steel used by Britsih Leyland!
He could talk for hours about how they 'saved money' by cutting corners by ignoring his advise on storage and wastage