I'm the proud owner of a new 3" APS turboback, and in less than two weeks it is dusty (AZ) and sooty (down to one cat!). What is the best way to keep my new exhaust shiny and clean? I assume it gets too hot for wax to stick; are there any protectants you can use to prevent soot and dirt build-up? And once it gets dirty, what is the best way to clean it? I've heard Windex, but I'm open to other suggestions.