i have possibly a dumb question. i recently upgraded from a 2004 to a 2012 Silverado. the new one has on-star and a basic CD mp3 player no sat radio but there is a button for it on the stereo. i like how directions show on the LCD of the stereo when using on-star. but i would like to at some point upgrade to an aftermarket stereo. but if i do that i don't want to get one with the same or less capabilities. is there one of those touchscreen nav stereo systems that will work with my current features while giving me the new ones? basically still have the onstar sourced directions still show on screen if i dont use its built in nav?