On a used 2017 RAV4 SE. It is see-through black, about 3 inches long, and flashes briefly when I start the car. Only thing I can think of is the remote start. Anyone know?
Mystery solved. It's a replacement antenna for the remote start. I've had the RAV4 for almost a year now, and never once used remote start. Oh, well. Thanks for your suggestion, JuneBug.What is printed on the unit? I can’t make it out in your photo.