I don't know if this is clear enough or what. Can you see the drawing on the bus? Amazing how the dusty bus has a picture of a flying dragon and it's not badly drawn.
People, you can try it on your car too. If you collect enough dust and dirt on your vehicle, you might even create a masterpiece like Van Gogh or Da Vinci.
If anyone can't see the drawing, blame it on my poor photo taking skills and my phone's camera. It's only 2.0 mega pixel after all. So unless someone get me the I phone or Blackberry, I'm sticking to my tough and reliable Sony Ericsson. ^^