SignalTrace “links devices that regularly travel together, correlating them to license plate.” It is a surveillance product that will sweep up and add all sorts of Bluetooth and other data to license plate readers, linking specific devices—and people—to cars.
For MAC spoofing, just do what Apple does; randomly generate a new MAC every minute or so.
I’ve actually got an app on my phone that makes it announce itself as a whole bunch of devices from TVs to pacemakers to headphones, with a rotating MAC. It’s interesting seeing what tries to connect to it.