The Guardian Knock, knock.
Car go beep beep.
Regular Radio 4 parents on the afternoon school run have been warmed up for the event with cheery plugs and requests for their children to send in ideas. Once the BBC announced in a u-turn last August that it would reinstate a trial speech radio slot for children, it's been full steam ahead. I listened to a preview with my son John, aged eight, who fits into the programme's target age group, of eight to 10 year olds - the Blue Peter band. Left to his own devices, he is a dedicated viewer of Robot Wars. I thought it only right to have him as a reality check in case sentiment misted up my judgment.