The tags are hidden on high-end cars when they are parked in public spots.
And unfortunately, AirTags' designed-in privacy might be so good that Apple cannot do much to help.
Track and Trace
Apples AirTags work by emitting a regular Bluetooth pulse.

Äức Trá»nh/Unsplash
But that doesn’t mean the system cannot be abused.
Putting an AirTag under a fuel flap?
How Can You Prevent This?

York Regional Police
Presumably, the owners of these high-end cars found the tags and realized what was happening.
But there are better ways to protect yourself than just chance.
This works for tags hidden in your car or dropped into your purse.
York Regional Police
The next version of iOSiOS 15.2has a new option to scan for hostile AirTags.
“That’s ironic,” writes AirTags userVertsix on the MacRumors forum.
It could automatically scan for tags when connected, for example.
Meanwhile, car owners must keep on guard at all times to notice any trackers.
Otherwise, the standard police advice applies.
If possible, park your car in your garage, put a lock on your diagnostic port, etc.
Everybody wins, except those car thieves.