hmmmm think i might have to do this aswell.
had a new bumper fitted by skoda after the drunk ran out infront of me.
noticed the other month that something was hanging down under the car.it was the plastic panel under the front end of the car.
im not totaly sure but i think they have screewed that onto the bottom of the bumper instead of pushing the lip up into the bumper and then screewing it on.
first pic on the second page of that pdf might
help you understand what im talkin about
not totaly sure but think i will check that out in the morning