He's at it , again!

This evening, our daughter rang and asked if I knew if some local farmers still sold bags of potatoes
She said the school was selling 50kg bags of spuds, for $45.00 as a fundraiser. She wanted to know if we could get them cheaper. I did some ringing around, and discovered that one farmer had one bag left, and they were $15.00. I said we would take them, and come out after dinner, and collect them. Neville had bought 10kgs from the super market, for $7.00, and is NOT impressed! I rang our daughter back, and she said she would be happy to go halves with us. She will sell half of them to her friend.
We duly tootled out to pick them up, but when we got going in the car, there was a noise, as though a piece of wire was caught on the car somewhere, and it was banging in the wind. Neville stopped the car and had a quick look, and found nothing. We set off again, but it was still making the noise. He pulled up further along and got out to have a proper look. Still could not find the source of the noise. It was nearly dark by now, but we continued on our way. Suddenly, he said, "I know what it is. I have left the other key in the door!" This key has a piece of tin on it, so he knows what it is for, as he has many keys for the car and the farm. He wound his window down and pulled it out of the door. Problem solved!