We have 3 kids, so yeah a car is really needed. They are missing out on loads with us not having a car which was our own doing as we both smoked and couldn't afford one. My wife has to catch busses and at weekends, taxis to and from work. This costs £50 per week.
We are both fully aware of the costs of owning a car, £300 spent on a car per month is better than £300 on tobacco is it not. Plus we can enjoy going out to kids parties because we can now actually get them there, a day trip to nature reserve, any Tussauds attractions out of our reach are not now. We can go camping over weekends, get the kids out and about. We have a full world of adventure open to us now. If its costs an extra £50 on top of our daily use in fuel to drive to the Lake district with the kids for a week end, its a small price to pay. Rather that than stay at home or go to the local chav park.
So to us, yes it is essential.