Originally Posted by suss6052
I would recommend looking closely at the ST grille, but it doesn't appear to have a larger opening, despite looking like it should.
If the openings are the same and it seems to mirror the standard grille for the upper opening, a large closed center section and then the open lower section where the grille shutter system would sit behind. Now if some one could demonstrate this by putting the images of the lower grille side by side (where you could see what was actually open it may prove this to be the case.
Just did a google search and every image of the ST I found that was a production model, like our model had an opening at the top of the grill for the intake, and an opening near the bottom, not very big, like ours, for the intercooler/radiator. But even though it's height is similar... the grill on the ST is wider than our center portion, so it will be a bit bigger. As I stated, easiest way to do it with a standard bumper would be to take a dremel to the side grill pieces and make them functional.
That said, there IS a larger opening at the very bottom of the grill, where they have a much wider air dam than the traditional Focus' small 4 holes.