WalleyeMikeIII
Full Access Member
I don't actually think it is a Google issue...yep that's when I use a Garmin, you can't put that kind of reliability on google, learned that a long long time ago
I can do the exact same thing on Google Maps installed on my iPhone, and guess what...the maps stay...for a year; just like google says.
My gut says it is GM/OnStar that auto expires the maps after 3 days, so you have to keep a data plan...but I don't know this to be a fact, it is just a guess.