Cd changer question

[Stilo Multijet 140bhp]

I've got the connect nav+ in my Stilo and i've got the problem of having to change the cd every time i want to use the navigator and i'm listening to music, so i've decided to put the cd changer in but the trouble is that I am very fond of using mp3 cd's; is there any cd changer that i can put unto my stilo that'll read mp3 and that i can use with the nav controls?? Or at least some other device that can read the nav cd so i can use the main cd slot for music??