It wasn't until The Detroit Free Press reported on General Motors' radio-tracking program — which monitored the listening habits of 90,000 drivers in the Los Angeles and Chicago areas for three months in late 2017 — that it became clear that the future of targeted advertising in cars is… well, it's practically already here.

GM captured minuted details such as station selection, volume level, and ZIP codes of vehicle owners, and then used the car's built-in Wi-Fi signal to upload the data to its servers. The goal was to determine the relationship between what drivers listen to and what they buy and then turn around and sell the data to advertisers and radio operators. And it got really specific: GM tracked a driver listening to country music who stopped at a Tim Horton's restaurant. (No data on that donut order, though.)

GM says the whole concept is still theoretical for now. No one's data has been sold (or "licensed," as GM prefers to call it). But GM spokesperson James Cain says that connected vehicle data can help develop more accurate ways to measure radio listenership. That could prove useful to the terrestrial radio industry, which continues to lose territory and ad dollars to digital streaming services like YouTube, Spotify, and Apple Music. And GM sounds happy with the results.