This is the offside one in my Sportshatch looking forwards into the front edge of the wheelarch, which I removed and plated over before I sold the car. They're not there at all in the Firenza, so I assume they've been plated over in any case. Should give you an idea of position though.
The strenghtening "lip" around the plate is basically a mud trap, so unless they're inspected and cleaned very regularly, this is what happens.