I had a similar problem where the passenger side skirt came loose at the front, hanging out like some sort of pedestrian sweeper. Fortunately, I saw it in the side-view mirror just before pulling out onto a faster road. I took it off (no damage, except the loss of the front fastener) and drove without the skirt for a few weeks waiting for the part. The car is ugly with the skirt removed.
The fastener itself was remarkably expensive, being a specialized screw (~$16). It seemed to be carbon-fiber instead of metal and had a weird, zig-zag thread on it. Basically, to tighten, you push in, turn 1/4 turn and then let it spring back out some. If it doesn't spring back out, it doesn't lock, hence the lost screw.
Don't expect it to act like a normal screw. Just turn it 1/4 turn and let it lock and test to make sure it won't pull out.
It won't help you with this skirt, but it might help you with the NEXT one.
The fastener itself was remarkably expensive, being a specialized screw (~$16). It seemed to be carbon-fiber instead of metal and had a weird, zig-zag thread on it. Basically, to tighten, you push in, turn 1/4 turn and then let it spring back out some. If it doesn't spring back out, it doesn't lock, hence the lost screw.
Don't expect it to act like a normal screw. Just turn it 1/4 turn and let it lock and test to make sure it won't pull out.
It won't help you with this skirt, but it might help you with the NEXT one.