oh well you'd hate me - I've just driven from my house that's bigger than I need (3 beds with 2 preschool DCs, if I was in social housing I'd have to pay the bedroom tax) in my DH's estate car that while not being high, is the same length and width as most 4X4s (and eats petrol) to pick DS up from preschool - and a journey of 0.3miles I could have walked (which I normally do, we were running late). I don't need a car this big for day to day, DH is a cyclist so for about 2 hours a week we need an estate car, far too expensive and a faff to hire a car every weekend, so for the bulk of the week we have a car that's bigger than we need.
I say for the bulk of hte week we have this, but at the moment we do actually own 2 cars, I have a little fiesta as well, but we're getting rid of it, we can't justify the expense of continuing to run 2 cars now that we only really need one (DH commutes by train), and of the two, the big car is the one that will suit all situations we need a car for, whereas the small car wouldn't.
My life, like most people in the UK, is full of things I don't really need, that aren't my basics - we could cope with no car, it would limit what we did, but we'd cope. We could cope with a much smaller house (using far less fuel to heat and light it), we could cope without meat, with less clothes, the DCs don't need their mountain of toys and we don't need most of the things we own/buy - but for the bulk of them, they make our lives a little bit better. They are selfish purchases, but few people with spare money make 100% unselfish choices.
A large car makes our life a little easier, it's selfish, but most humans are in some way selfish - you aren't selfish about cars, well done, you aren't selfish in one area of your life - look around you, anything in the room you are in now that you don't need that's taken fossil fuels to make/transport? Why do you have it if you don't need it? Because you wanted it? Because it made your life just a tiny bit easier/nicer?