Personal car ownership is completely unsustainable & unnecessary. Most privately owned cars spend 95% of the time sitting idle, so over the lifetime of the car, its efficiency, taking into account the resources that went into its manufacture, is very low. Private car ownership usually means that the car owner will use the car as their default mode of transport. Rather than considering what is the most effective way of making a particular journey, a car owner will often hop into the car, even if it would be cheaper/more efficient/quicker/less damaging to the environment to walk, or cycle, or use public transport. Car clubs offer pay-as-you-go car use, so if a journey really can't be made in any other way (eg heavy shopping to transport, no available public transport) then a car can be hired for a couple of hours. Every available car club car typically takes 5 private cars off the road. Drivers decide not to bother with the hassle of taxing, maintaining, insuring a private car, when for a small fee they can just book one for when they need one. Because car club cars are used more intensively, their use in relation to manufacture becomes more efficient. There are commercial car club operators (Whizz-Go in Leeds), but in some areas groups of local people have set up their own informal clubs. I suppose the ideal car club would run electric cars that plug-in to a renewable power source! Carplus has information and resources to help groups organise their own car sharing clubs.