Using Apple Air Tags instead of a dedicated tracker, if that’s your bag, is a bit of a futile exercise.
They will chirp when separated/not in BT range with their paired iPhones, alerting anyone nearby, when disconnected from their phone for a period of time (Apple say between 8 and 24 hours).
You can remove the speaker, and their are YT videos on how to do this, but they also have a anti stalking mode, meaning when moving anyone with an iPhone that they are travelling with and without the paired phone in range will be alerted on their iPhone a tracker is near.
So even if you remove the speaker, if the driver has an iPhone, they will be alerted and if you have not removed the speaker, they will, eventually, hear a chirp.
Effectively they are not designed to track things that move independent of the owner (kids, pets, cars), they are designed to track things you drop or leave behind, keys, wallets, backpacks etc and any other use has some sort of mechanism that makes them poor car trackers.
So the only real effective use case is the speaker removed and the thief not having an iPhone and the car being stationary when someone with an iPhone pings it.