I received the product and since I had already assembled the StowAway carrier previously, I had to remove it from the frame prior to installing the exhaust shield. Once the carrier was removed, I marked and drilled the holes as noted in the directions. I then mounted the shield and attempted to tighten it to the frame using the self-tapping screws provided. However, this proved to be a futile attempt since the screws would not self-tap fully, only inserting into the frame partly. I remedied this by removing the screws and adding lock washers and then tightening the screws as much as possible. It would seem to me that these holes should be pre-drilled and tapped on both the driver and passenger side of the frame at the factory. If they are not used, no harm but it would make it much easier for the user by having them already predrilled/tapped.