I assume the navigation on the 2004 QP is the same as a 2004 Spyder / Coupe. Are you looking for the entire set or just a single CD? Individual CD's and sets come up regularly on EBay. By all accounts on the forum, the Maserati system isn't worth the effort. I can't get the nav to work or my car was never equipped with it - probably the latter. Additionally, you can't use your CD player for audio if you're using it for navigation. Apart from it looking pretty, no point in using it versus a Tom Tom, Garmin, etc..
04 Spyder GT - 11323 - SOLD
86 Ferrari 328 GTS blu sera