Ready to trade your old car in for a shiny new mobile hotspot? AT&T and GM are using the international platform that is Mobile World Congress to announce a partnership that'll bring the carrier's LTE network to "millions of cars" under the Chevrolet, Buick, GMC and Cadillac umbrellas. The rollout is set to hit the 2015 models due out in 2014 in the US and Canada. The partnership with GM-owned OnStar will bring AT&T connectivity to a variety of services, including safety, diagnostics, infotainment and safety -- the carrier's president of emerging enterpris
