Seals on bottom of engine/radiator passage

[E90M3CDFR]

FYI: there are two rubber strips that seal the cavity that flows air through the bottom cooler, passing it down under the car. One of these pieces came loose and almost fell off my car while driving in Germany (ie higher than normal speeds). Fortunately, I saw it hanging under the front. The other was working its way loose. Here are two photos; second one shows where the piece was missing and after I replaced it. On another posting I found the part number and it isn't expensive, but if you can catch it before you lose it, you'll save a few bucks.

I don't know what the downside of losing this seal may be: I'm guessing aerodynamics under car are slightly disturbed, maybe heat from the engine is then being ducted back into the undertray; perhaps the undertray will work its ways loose over time as air is channeled between it and the engine. At any rate, something to check on periodically and in my case I used some glue to fix the rubber seals on more permanntly.

Oh...and when I first noted this issue to my dealer...they put the piece back on the small lip that is part of the bumper cover! Fortunately, it came off easily and is now where it should be.

[Singletrack]

I had an issue where one of these guys was working iself off as well. Although in my case, it was caused by hitting road debris - ice block to be precise.

Good informative post - I bet others will have this issue.