https://maxtondesignusa.net/
They're based in Illinois.
Mike Augustynski is the name of the gentleman i had email exchanged with. Below is the last reply with order specifics.
I will put these parts on our next import order for you.
Here is your pricing, parts in Gloss Black, free shipping within continental US included.
It would take 3-8 weeks for our next import bulk shipment to get here.
BM-X5-05-MPACK-FD1G+FD1RG - FRONT SPLITTER BMW X5 G05 M-PACK - $234.00
BM-X5-05-MPACK-SD1G - SIDE SKIRTS DIFFUSERS BMW X5 G05 M-PACK - $234.00
When i asked for discount Mr. Augustynski gave me 10% off without any hesitation. So with the discount each item came out to $234 shipping incl. 3 to 8 weeks time. He even said no prepay. There is no mention of BMW parts on their website but they will order them for you.
This is where you will find all the parts.
https://maxtondesign.com/