Electronic Upgrade
 

I would like to upgrade my corrent AM/FM cassette with changer to the unit with integrated cell and GPS. Where is the best place to find such a unit (I find a couple on EBay) and will they be plug and play or will they need the navagation disk along with it? I am thinking if it has been installed before on a nother vehicle, the navagation info will already be installed but not sure.