GLAXY NAVIGATION CD?

I WANT AN UPDATED VERSION OF NAVIGATION CD FOR MY FORD GALAXY 2002 GHIA, HAS ANY ONE CAN ADVICE ME WHERE CAN BUY ONE, I DO NOT WANT SPENT MEGA, AND I DO NOT KNOW WHAT IS THE PART NUMBER THAT I WILL HAVE TO LOOK.THE CD I ALREADY HAVE IS A BLAUPUNKUT TELEATLES 2000/01.