I actually work as an automotive dealer, and some of my best tools are a power washer, Simple Green cleaner/degreaser, and Mr. Clean Magic Erasers. It sounds crazy, but the magic erasers are effective at cleaning up leather seats. They remove all of the grime from even the cleanest looking seats! Just make sure to wipe them down after with some leather conditioner. If you have access to a hot steam extractor (something like a Rug Doctor), that is what I use for doing the carpets and getting out stains. Another great product is Tuff Stuff, which my coworker recommended to me. This stuff will dissolve any stain/grime on a hard surface and virtually eliminate stains on fabric surfaces. Good luck keeping the car looking showroom new!
