The car gps has never frozen or given any problems other than an occasional bad connection where the wires plug in. The sd card comes from OFSC, ontario federation of snowmobile clubs. I believe you can just download the data for the maps, but a friend buys a new updated version every year and gives me his old one. He is using a montana, the cadillac of offroad gps, but the unit and mounts were very expensive, and then you need to worry about losing it or have it stolen.