Rear view issues

We went to the Heritage Motor Museum at Gaydon today and had a really interesting time - some fabulous cars there and a fascinating portrayal of the history of the British Motor Industry and its movers and shakers. I had forgotten about these strange things we used to be able to buy to stick on the rear windows of cars allegedly to maintain visibility through the rear window. Now we just flick a switch and the mist clears! If only all things in life were that easy. Part time day off number 2 - very interesting and full. How do I have time to go to work?