I'm with melvin on this one. i have the changer full but each disc only holds about 20 tracks... not like a real mp3 cd player. heck the cheap aftermarket deck i put in my jeep would play the mp3s. Sure was nice having a hundred tracks on a disc. I figured the gxp would be able to play them and hold all i would ever need... nope. So i just do like melvin and plug in my phone... that way it plays music and GPS automatically interrupts and plays through car speakers too.