Hi: I just recently bought a 2002 Prius with navigation. I decided to purchase an upgrade disk. I bought version 4.2 Toyota Nav disk and my system says that it can not read the disk. The disk is in fine shape. My present disk is the orig dvd that came with the car in 2002. Is there a special disk only for Prius? All that I have read suggests that any Toyota disk will work. The numbers on the disk are essentially the same except the last two on mine has 81 as the last numbers and the newer one has 86. I thought this to be just a newer version. If you anyone has any information please let me know
Toyota has marketed several generations of NAV. Each one uses data disks that are not compatible with the other generations. The 4.2 version you bought is most likely for a second generation system, while your car has the first generation.