RhombusRovers

I have a Car Magnet TB, and have activated it as a trackable. I'm assuming it always stays "in the hands of the owner", but my goal is to see how many states others spot me and log it accordingly. If it is always in my hands, it appears the mileage calculator will never update? Am I going about this incorrectly, or are car magnets a bit of a square peg in a round hole when it comes to trackables? Thanks in advance - RhombusRovers