I have a book written by an ex CHP copper who is a Mopar enthusiast.
He does elaborate on the purchasing procedures of the CHP, which was at the time the single biggest customer of squad cars
and even had their own proving grounds. Their decisions influenced other police departments' choices, i.e., what's good enough
for those Californian fruitcakes will certainly serve us well.
The specifications outlined were much tighter than one would imagine and something as trivial as the wheelbase being half an inch
too short would catapult an otherwise perfectly capable car off the shopping list.
He fully admits that some of those specs didn't necessarily follow rationale or common sense, the minimum wheelbase and heft
of the cars being but two of them. It took them until 1969 to realise that the intermediates were swifter, nimbler and needed less
petrol, thus were actually better suited for many duties than the big cars were.
It would be interesting to learn what the requirement catalog for British police cars was and which organisation was responsible for it.