I got my data plan straight through AT&T...$20/month. This way when we have grandkids in the vehicle they can stream movies on trips. Don’t have an onstar plan, don’t use the app. The app was a novelty in my opinion while for some it may have some actual use. It wasn’t worth the money to me. Like everyone else these days going to a subscription model and nickel and diming you...by the time you add up all your monthly subscription fees and the annual cost, is it worth it? Somethings yes, many things no.