Yeah, as I recall it is from the 99-04 Mach 1 Mustang (the only years it was made). It required some trimming at the ends (it's too long where it wraps around toward the wheels), but that was pretty easy to do.
I honestly don't recall how I drilled the holes. I think I just used the holes in the lip piece and drilled through the lower OEM lip of the car. That said, I did it almost 10 years ago and that car is long gone, so my memory could be hazy. But however I did it, it wasn't very difficult as I recall.
Yeah, wonder if that car is still around. I know Albert (another member here) bought it to use as his daily driver, but haven't heard from him in a couple years...
Anyhow, good luck!
Josh