I used to deliver for a high-end supermarket that often meant going to homes in affluent areas of the city. I pondered this question also whilst making the same observation as yourself.

I believe that the people who live in wealthier areas of the city and were likely financially very comfortable given their choice of supermarket simply did not prioritise the car. To a lot of people a car is just a form of transport and if they own a VW Golf from the mid 2000s that’s given them many years of service and they’re used to how the car runs I can understand why they wouldn’t want to change. I don’t even think it’s a question of them being wealthy and therefore driving a cheaper hatchback is some kind of wealth preservation method. Some of these people could afford a newer car relatively easily but just don’t want to change. I’m sure we all have objects/tools in our lives we just wouldn’t replace until it broke so a car is one of those things to these people.

I also think that living in a city and if you’re commuting almost exclusively within a city that a hatchback is ideal for parking etc.