Blimey LeafyHouse - please tell me where you are buying your cars, as I can't get deals like that anywhere I've looked.
Unless you live rurally, it is possible to do the school run and get to work on public transport- if you live in a very big city which is what I'm talking about.
What a ridiculous generalisation. Can't begin to believe you actually think this is a fact for everybody - you can't be that ignorant, surely? 
You keep cracking on about people not needing to drive in to City Centres, and mentioning Birmingham.
Let me tell you about one building in Birmingham City Centre. It is Birmingham Children's Hospital. Now, personally, I have taken my otherwise fit and well ds there, on the bus, for an audiology appointment. Many, many parents aren't so fortunate as to have such mobile dc. Children going in to BCH have - as it might be expected - all sorts of illnesses and disabilities. There are dc with wheelchairs, that need to be on oxygen, that are immune deficient, etc., etc. There are hundreds of families from all over the Midlands, the East of the country, the North East, Wales, and potentially a lot of other places that have to travel for specialist care at BCH. Putting aside those thousands of people, then let's look at the staff.
Cleaners, maintenance staff, laundry staff, kitchen staff, porters etc - all will be on low wages. Nursing staff and many, many other medical staff will be working all kinds of shift patterns that mean they have to be there before public transport starts or after it stops. Therapists, social workers, play workers, outreach nursing teams etc etc all have to work in different parts of the City / do home visit / attend Child protection conferences / attend EHCP meetings / planning meetings, etc etc, etc, - you can't do that sort of job and make all your appts without driving.
There's probably dozens of other people who need cars and work at BCH - JUST ONE BUILDING, in just one of the Cities you mention. It's so ludicrous to just throw out a wild statement about how EVERYBODY can use buses to get to work.