To play devils advocate, there are a few reasons off the top of my head: 1. More people have phones than cars 2. Cars take someone to a general location (i.e

To play devils advocate, there are a few reasons off the top of my head: 1. More people have phones than cars 2. Cars take someone to a general location (i.e a shopping mall carpark) but phones are precise enough to say which section of a store (or hospital) you are in 3. Car manufacturers can't inherently link the passengers of the car to the driver, or to each other 4. Manufacturers of cars don't have ads as a core business model That's not to say what car manufacturers are doing isn't scummy -- it deserves more light. But what Google does affects more people in a much more complex way. Google doing this essentially takes attention away from these smaller cases of privacy violations -- if the Google issue is solved (and I'm using Google here as a supplement for "phone tracking") then the world would turn their focus to the smaller issues like car tracking.