If you're willing to spend money on the problem, there are devices designed to get around those obstacles. Devices which can be attached to a car and draw power from it, devices designed to run intermittently to extend running time, particularly efficient devices that run for longer than consumer-grade navigation chips do, etc. Not that you can get something standalone as efficient as an AirTag, but they're not as limited as you might hope.
Biting the hand that feeds IT
