I recently purchased a 2006 Toyota Tundra Limited that has stock Navigation but the disk is missing. Dealership price is $250 but I am hoping someone knows how to get ones cheaper. I am worried about purchasing an older one though and not having it work with my model. Also, how much difference is there in the older disks compared to the newer ones, if they are compatible. Anyone very knowledgable out there, I would love you assistance. THanks.