Because all they do is spend all day shopping or "lunching", so they don't actually have any idea how to drive the car that "hubby darling" bought for them. Their only practice is doing the school pick up, where they have to show off to the other 4x4 mum driver's, that they are actually skilled and in control of what they're doing.. . I'd like to confess that mum's driving MPV's in Hants are actually very skillful driver's, whatever the time of day.