Don't know if this helps or not but as a nanny I do around 3000 miles a year, so I expect childminders are going to be similar - though obviously depends on distances involved in doing things like the school runs.
Motor insurance £379 once all the bits added together, you know how insurance works, there is the legal cover, the car seat cover, keycare, loan car, etc.
We used to walk to and from school, so much better than driving. Alas once eldest went to junior school it meant we had to drive, walking was not an option as there is no path and it's too far, plus had to be at infant school in time to do the drop off. So it will depend on the children you childmind, if you are just going to one school walking is an option for you but if you are doing multiple drops, it's harder. Then there are the outings... if you are town based and within easy walk of places, or a bus ride, then that means you won't need a car but if you are in a small rural village, miles from anywhere, it's a different matter. Going swimming is a 22 mile round trip for us! Even the school run is 4 miles each time.