Originally posted by Fissy
Muffler ? Who said anything about I muffler ? I was just reading a good book entitled "Brown Spots on the Ceiling" by Hu Flung Poo. Excellent reading if you get a chance 
I'm pretty sure that they are from the exhaust but on the bright side, it comes off relatively easily.
No, I don't have a camera but am looking to purchase one for situations like this and many others. Please see "... Camcorder vs. Camera" post and help me out. 
Hu Flung what?? That sounds like something my kids would do... as for the pictures, you really don't want to remember that Hu Dung Yuuu??