[capnjack52]

For those who have had their front wheel well air dams ripped apart by parking lot bump stops, it appears that BMW have made a design change to help with this problem. I just purchased replacements after trying and failing to repair the torn up parts. However, when I compared them to the originals, I found that they are at least an inch shorter in depth. After installing them (not difficult), I discovered that they now clear the typical bump stop seen in most US parking garages/lots. Don't know how or if they change underbody aerodynamics, but they sure make parking less risky!

According to RealOEM.com http://www.realoem.com/bmw/showparts...51&fg=75&hl=43, the old part numbers for "Cover, bottom left" (51757186517) and "Cover, bottom right" (51757186518) were superseded in August, 2012, by new part numbers 51757312829 [left] and 51757312830 [right].

Hope this is helpful.

Cheers!

[45ACP]

Ouch... depending on the vendor they're about $22-27 each + shipping.

[nabego]

that is what makes this piece? what for?

[capnjack52]

Originally Posted by nabego

that is what makes this piece? what for?

I'm not an aerodynamicist, but I suspect these pieces help smooth the airflow around the front tires. They also have a slot behind the dam that's open to the engine bay, so perhaps they also help create a vacuum to draw more air through the bay. If anyone is more qualified to answer, please jump in! BTW, as observed by 45ACP, I paid $27.69 each + $10 shipping. As BMW body bits go, this wasn't too bad - hey, my local dealership wanted over $50 apiece!

Cheers!

[MWPos]

my dealership parts department will match getbmwparts.com prices. Give your local shop the opportunity to compete and they probably will. Getbmwparts really is just the Internet side of a dealership's parts department.

[nabego]

Can be related to the problem of vibration?

[Jamese93]

Iirc they're to block spray and slush in the winter from going straight onto your tyre before it rotates to the ground.. Informed by BMW themselves so must be true :-)

[The X Men]

Originally Posted by Jamese93

Iirc they're to block spray and slush in the winter from going straight onto your tyre before it rotates to the ground.. Informed by BMW themselves so must be true :-)

They are there to reduce drag:

http://www.autospeed.com/cms/article...-Part-2&A=2456