Rear valance question - C7.5 A6 S-line vs S6

[Bonz54]

Hopefully someone knows the answer to this:

Here is the part number for the S6 rear valance - https://parts.audiusa.com/p/Audi__/Valance-Panel-Lower/64360585/4G0807521M3FZ.html

Here is the part number for the A6/S-line rear valance (used on the competition model and is the same visually as the S6 rear valance) - https://parts.audiusa.com/p/Audi_2018_/Valance-Panel-Lower/64360588/4G0807521R3FZ.html

Obviously the only difference in the part number is the "M" for the S6 and the "R" for the A6/S-line.

I have a 2018 A6 sport w/S-line. I THINK I want the R part number above but is there a difference between the two? I read that others have retrofitted an S6 rear valance but is the A6 part number above the easier route for the same result?

Thanks!

[widebodyfx]

This one is confusing, I think the S6 diffuser is multipiece and the S line diffusers are all one piece. They have similar appearances but more details in the S6, I looked up photos of competition A6s and it looks similar to S line 1 piece but maybe there are variants out there.

[Speedooooo]

Check out my thread. There is a slight difference between the C7.5 S6 and A6 S line diffuser. The diffuser fits okay after trimming that extra piece. It does jut out a bit.

https://www.audizine.com/forum/showthread.php/907728-C7-5-S6-rear-diffuser-not-fitting-C7-5-A6-3-0T