Question on front lip installations

[axmea?]

I noticed that most front lip installs whether carbon, FRP, or plain poly u are mounted using brackets and self tapping screws on the bottoms, self tapping screws on the inside of the fenders, and 3M heavy duty mounting tape on the front edges. My question: How does it hold up? A body shop that I took the lip to for painting and install was hesitant in installing it saying it would not stay secured enough considering how low the car already is (stock height) and the mounting options. They are saying that the mounting tape and stock brackets that came with the lip is not enough and need to be modified. I have springs ready to be installed next week.

So now I am concerned regardless of who installs it. Will this stay securely. I don't drive like a maniac on driveways and pretty careful in getting in driveways at an angle. Your feedback and suggestions appreciated.