Sorry savvy, but I haven't had to remove any stains yet, so I don't have any proven solution for you. Once you get them off, a coat of good carnuba wax or better yet a synthetic acrylic wax such as Klasse All-in-One may make them easier to remove if they reappear. Btw, the Klasse AIO is an excellent cleaner. I believe it uses a mild solvent to clean so it is non abrasive (or at least so micro-fine that it doesn't leave scratches or swirl marks). It also has an acrylic wax component that outlasts any carnuba based product. Good stuff and I highly reccommend. Sold mostly on-line, so just google it.

For the NAVI screen, I picked up a container of pre-moistened computer screen wipes from Walmart. They come in a container like "baby wipes" (if you know what those are), except smaller container. The wipes pull out one at a time and work great. Plus the solution is supposedly "anti-static" to repel dust.