I just had a random thought.. You know how some people stick something on the top of their vehicle's radio antenna to make it easy to find in a car park? Like a giant plastic sunflower,
etc.?
Or they click their remote and the vehicle feeps for a 'Here I Am!' response?
What if someone combined these two, and instead of a remote-click resulting in a honk, it triggered a corona discharge from the tip of the antenna?

Admittedly you'd have to take care to not fry bystanders (though making them jump out of their shoon is okey

), and I'm not sure the geometry of the antenna tip would lend itself to this, but..
..wouldn't it be Neat Stuff?