Please excuse my lack of design skill. I started learning Blender only last week.

This is a vortex generaton for a car. A number of these placed in the right areas near the back of a car can reduce drag by a few percent.

The stl file is simply the airfoil or wing. I print it with a raft and use the raft as the mount surface using double sided foam tape. If one is lost while driving I can simply print another. I print the file scaled up 2x.