Sure you did, a contract of sale. That makes you the owner of the device. Should another person be able to access all your computers sensor data just because you let the person use your computer?

Of course, this data is yours, same with the car.

Of course my friend can use the sensor data of my car if I let him/her. The question is whether the car company can claim that the sensor data that my friend collects while driving is theirs without informing him/her of it.