Many cheap gps trackers support "vibration wake up", they go to sleep after a while they've been still and wake up when you start the car. They run in sleep mod

Many cheap gps trackers support "vibration wake up", they go to sleep after a while they've been still and wake up when you start the car. They run in sleep mode at least a week on an internal battery so charging them only whole the car is on is not a problem. Traccar supports many protocols so you are usually able to buy a random tracker and reconfigure it to work with your traccar instance.