S550 Coupe wheel spacers
 

I have a 2017 S550 Coupe with the original AMG 20"multispoke wheels. They are 20x8.5 ET 38 front and 20x9.5 ET38 rear. I have read that people recommend 15mm spacers front and 10mm rear when using stock wheels which would make the offset effectively 23mm front and 28mm rear. Anyone have an opinion on that? I am looking for a flush fitment.
Also, if anyone knows what offsets Carlsson/Lorinser etc are using please let me know thanks.

I have the same wheels on my '15 S550 Coupe and running 15mm front and 12mm rear. I was advised 10mm spacers would not clear the 4MATIC hub-centric ring and sit flush against the hub.

All looks great with the flush look you are looking for.

However, In the short time since installation with only a couple of high-speed runs - I seem to have a slight vibration over 90 MPH or so. I will eventually get wheels with the 'correct' offsets to ditch the spacers.

Thanks for the info! So I guess if I made wheels custom with a +10mm offset there should be no issue with the hubcentric ring since I would not be using spacers.

Correct.