For those who have done this install I had a few questions.

1. Is stock undertray necessary to install the lip?
2. Lip looks like it hooks onto something and then you install screws that hold onto that same part. Is this the way yours was installed?
3. There are no screw holes on the ends, so nothing holds the sides. Did you manually drill holes in the sides or left it the way it was?
4. My greddy lip would make me scrap driveways, do you have the same problem after installing this lip?