The Kansas Highway patrol installed one on the frame rail of my NA car, in the engine compartment.
I'll try and post a pic.
It's on the tube that supports the rollbar, right above the battery>
He told me all I needed was the one ID plate for a "specially built vehicle".,,,,,,,but I suppose you could also put one on the top corner of the dash like most productgion cars too,,,if you wanted to have 2 badges?