I have said this before ---- I would just emphasize the point: I recommend for everyone to practice removing and installing the wheel skirts 10 or 20 times. Get good at it. I've had 3 new Insights, driven them 142,000 miles, and never had a loose skirt. (I remove them often for cleaning, rotating tires, etc.) Many are the horror stories I hear about one falling off, usually from a service technician not installing it correctly.
The skirts and fasteners are designed very well, and they work great. When installing, just place it flat, 2 inches below it's target point. Then, while holding all edges in FLAT, slide the skirt upwards into place, making sure all tabs have been grabbed. It will stay in place by itself. It should look tight, with no gaps. Finally, insert each bolt and rotate clockwise a quarter turn. You can carefully "feel" the slight tightening as you turn the bolt. (use a giant screwdriver or the tool in your Honda toolkit)