[fwungy]

New cars have 3G cellular transmitters constantly sending telemetry data. This started becoming common in 2012.

[tmerc]

https://news.ycombinator.com/item?id=37971038

4g now. 3g was turned off causing these cars to drain the battery searching for signal.

[delfinom]

Depends on the brand still. Honda for example only does that to the top tier touring trims because it's part of their remote-remote start offering for that trim (that you have to subscribe to)