So if you look at my latest threads, I have made a Frankenstein, E38/E39 M5 front bumper made to fit my 740i sport. What I am trying to do is to figure out how to set up the brake cooling air ducts. The bottom half of the bumper is from the E39 M5 bumper. My choices are either to cut a hole in the side fender liner or to use a E39 540i air brake duct that will feed into the existing E38 duct system. Does anyone have the dimensions of these part numbers: 51117890013 and 51117890014? The end that feeds into the car is what I need the dimensions of. Thanks.