GM brought a Cadillac ATS to Mobile World Congress this week. This isn't a run-of-the-mill ATS, though — it's fitted with a number of LTE services billed as "concepts," meaning we may or may not see them when GM starts rolling out LTE on its production cars next year.

The big unknown is pricing

Notably, the services aren't just consumptive — one demo sends live feeds from the car's exterior cameras to an iPad, for instance, so you could keep an eye out for miscreants trying to mess with your ride from the comfort of your home. Another example streams live video from a number of networks — MTV, Fox News, and Lifetime, just to name a few — to the center console of the car. The spokesperson who demoed the system for us mentioned that it "shouldn't" operate while the car is driving (of course, Tesla offers a full web browser in the console, so anything's possible).

Other features include a standard-issue Wi-Fi hotspot available to passengers of the car and over-the-air app download, a pretty big deal now that GM has opened its app framework to developers. I installed The Weather Channel while sitting in the passenger seat — it didn't take more than a few seconds.

These are all well and good, but the big unknown is pricing: neither AT&T nor GM have been willing to comment on how LTE service will be billed once it launches on 2014 model vehicles, and it's easy to see how access to Pandora from the dashboard could kill even the heartiest data plan in a matter of days for frequent drivers.