As cars get ever more connected, sharing your already-strangled data account with the family--or just adding a new drain on it for yourself--can be troublesome. Having a separate data plan just for the car can be expensive. Audi is aiming to change that.

With a new $15 per month plan via T-Mobile, Audi now offers the most affordable in-car data plan on the market. The data plan enables access to the advanced functions of the Audi Connect system, like Google Earth, Google Voice Local Search, and more, while on the move.

There's a small hitch in the deal, however: it's not priced by the month. In fact, it's bundled as a 30-month plan for $450. For a month-to-month plan, the price is $30 per month. A one-year plan at $324 ($27 per month) and a two-year plan at $600 ($25 per month) are also available.

Whichever rate you're paying, you can also use the data plan for in-vehicle shared Wi-Fi access, enabling any passenger to get online with their tablets, laptops, or smartphones--up to eight devices at once.

Specifics of the plan, including data speeds and allowances, aren't disclosed. All Audi vehicles equipped with the Audi Connect system are eligible.