From Wired:

[Remote-controlling a Jeep] is possible only because Chrysler, like practically all carmakers, is doing its best to turn the modern automobile into a smartphone. Uconnect, an Internet-connected computer feature in hundreds of thousands of Fiat Chrysler cars, SUVs, and trucks, controls the vehicle’s entertainment and navigation, enables phone calls, and even offers a Wi-Fi hot spot. And thanks to one vulnerable element… Uconnect’s cellular connection also lets anyone who knows the car’s IP address gain access from anywhere in the country.