most cars use DVDs for the nav. Depending on car year, make model, you can contact the nearest delaership for update availability. Navtech supllies the DVDs for most manufacturers, you can call their toll-free number also to inquire
I updated the GPS in my 2003 Acura a few months ago. Alpine supplies the unit and their price for the updated disc was cheaper that the same disc from Acura. Find out the supplier...who makes it for the car you own? The dealer's part dept. will know. Contact them. There was a big difference in the new maps and ugraded program. All my previous addresses and preferences were not lost when I upgraded. It was an easy process.
