I grabbed some Pontiac Arrowhead splashguards from the dealership. Part #19213387. I grabbed two pairs.

I see on the front there are some bolt holes I can utilize.

But on the back there's nothing to use. Am I just drilling my own holes then? Trying to protect the rockers as best I can because mine are in pristine condition. I know the back guards won't help with this, but I want them at all four wheels so it looks balanced.