At $50 each, I did not want one of my louvres to fall off
First, I locates where I wanted my side emblems and then drilled three holes for "studs" that would not be seen when the emblems where installed - (I probably could have done it with two.) The studs are SS flat head machine screws.
This is a view from the other side - and you can see the nuts that will hold the studs in place.
I had a piece of aluminum angle from Home Depot, cut it to size and rounded the corners. I then attached the angle with 3 button head machine screws to the top of the louvres. You would really have to get down on you hands and knees to see them. I drilled large holes in the aluminum to fit around the nuts that are on the studs. The louvres then get bolted onto the studs with a larger washer and another nut.
They are pretty easy to remove for cleaning or access to the master cylinder area, and I don't think they will fall off. The emblems are held on with double sided, mounting tape