What is the purpose of the holes in the lower bumper lip, or air dam? Is something supposed to attach to them? Mine has sections cut out by the PO, I'm debating cutting the whole thing off if nothing fits there.

 

Pictures?

 

I may have answered my own question. I was looking for a picture online, came across a bumper on ebay that perfectly depicts this. Apparently, there is a flap that attaches.
You can see it here on the left and missing on the right...guess it's called a 'deflector lip'?

 

AS yes, the "deflector lip". Helps with the aerodynamics of the air flow under the car and through the engine bay.

 

Is this a standard part or accessory? It seems lots of bumpers are missing these. I lookup part numbers and they look like just the sides with 4 holes, nothing in the middle?

 

It is a standard part. The LCI models have the two smaller ones on the sides. The early cars had one long piece.

https://www.realoem.com/bmw/enUS/sho...diagId=51_6220

https://www.ecstuning.com/b-genuine-...t/51112755337/

 

It also warns you right before you drag the rest of the bumper on the curb. The dam is cheap compared to the bumper

 

Thank you, all the diagrams I looked at were showing the small pieces. Now I have the correct part number!