A lot of new cars do have internet built in whether that is exposed for your use or not.
My 2014 Chevy gave me 2 years of their mobile app which could unlock/lock the car via cellular for free. I know the car still has a data connection available because if I play songs via bluetooth it pulls in album art that doesn't exist on my phone via Gracenote. I can also hit the OnStar button and talk to someone via the car and I don't pay for that.
That Chevy lock/unlock API may not be a public API but there is nothing stopping someone from reversing it. Or just signing up to use it: https://developer.gm.com/vehicle-apis
Most modern cars offer the same features.