I sold one to someone on the board a while ago, to test fit it to the Borla headers.
The skidplates fit between the headers, not over them. You would have to grind the holes to make them a little larger, and add some spacers at the rear of the plate (a piece of square tubing, or some washers or something). I think it was Paul Sakai.
I've also made a HUGE 1/4" rally plate for a customer with Borla headers. It was 3' x 4' and HEAVY, but indestructible! You can contact d00f for comments on that one.