I had the same problem and purchased a screen protector from Ebya for $15 shipped, I think it is a good investment, my concern was not only finerprints but also scratches. the screen protector still shows fingerprints but you can clean it too and dont have to worry about the screen itself.
Nav Screen Cleaning
in Lexus Detailing and Car Care Forum
Posted
I had the same problem and purchased a screen protector from Ebya for $15 shipped, I think it is a good investment, my concern was not only finerprints but also scratches. the screen protector still shows fingerprints but you can clean it too and dont have to worry about the screen itself.