1998 E300 turbo diesel. Need to replace the air filter box (warped clips missing) checking various websites I ordered part A6020902501 (websites indicate this was correct part). Part came in box with original MB parts sticker and emblem on box. My question: Looking inside (after removing the new filter, which looks like the old filter) on the air intake side is a chrome(?)/mirror like insert which the old box did not have. Further there is a small hole (1/8 or 3/16) in the box there the intake hose meets it. Can anyone explain the difference between the old and new box. I realize the car is 26 years old, but it the difference an upgrade and if so why?