My grandson was a runner. His mom sewed loops in all his pants pockets and attached a Jiobit, which notified her of his whereabouts. It would announce to her through her phone that "calvin is on XX street' and if she didn't WANT him to be there, she had a quick heads up as to where to look for him.
The trick with ANY location device is the fact you do have to be diligent with making sure they wear them...for an adult--this would work, also an APPLE watch (all my gkids wear these)..they can communicate with their mom and she can know where they are all the time.
Are you talking about something a person wears, or is placed in a car? If you want something that is wearable, you need to consider if the person will keep it on.
The trick with ANY location device is the fact you do have to be diligent with making sure they wear them...for an adult--this would work, also an APPLE watch (all my gkids wear these)..they can communicate with their mom and she can know where they are all the time.
Apple AirTag for the car.