MMi
 

Will there be a flash for the old MMI on early model 2014. Read that the new cars you can get 4G and pick your carrier.

Actually, only the new 2015 A3 releasing this year has been announced with 4G using AT&T. It's not clear what, if any, path will be available for other current models. It's more than just software - just like a phone, the car will likely also need different hardware which probably won't be an inexpensive upgrade. Other series in the future will undoubtedly have 4G.

There will not be a software update that can take you to 4G. It's a hardware issue. 3G and 4G use entirely different radio receivers and it would be prohibitively expensive to do that hardware upgrade.