One of the rear springs on my vehicle had around the final 30mm of its bottom section broken off. This damage was not easily visible or detectable by touch. The ride height of the vehicle did not vary much, but there was sometimes an audible noise as I pulled off my driveway.
I bought rear parts online, namely SACHS brand. However, I had difficulties in obtaining the front parts, since both Eibach in the UK and Germany advised me to contact MB (Mercedes-Benz). I exchanged my item and received authentic AMG Eibach OEM as a replacement.
The little remark above fails to convey the extensive investigation I conducted to ensure accuracy. Fortunately, the previous fronts retained most of their component numbers and the colour code is apparent, however the rears lack this information. It was evident that they had been substituted by a prior owner.