Here is the proper setup to getting a fairing that mounts directly to your factory aero bars. My last piece shows either today or tomorrow and I will put it on.
Inno universal fairing, size medium, part# INA261
Make sure to include the long-bolt kit.
Their medium fairing fits just inside the two raised sides and the clamps are designed to fit over factory bars. Because two of the clamps will go over the jaws on the outsides of the bars the long bolt kit is designed to work for this. This is the only setup I have found that does not involve cutting, gluing, splicing, praying, zip-tying, reversing, etc.