auto dimming

why are Mercedes so hard to improve, the software's all locked or too stupid to work with and there's no knowledge base sharing how to guides for pennies on the second car, I have added and coded myself using only genuine parts and software the features in the list below exactly as though it...

Can anyone source a part number for the above, please? Or tell me how I could go about it. I can't readily find the part on the .ru site let alone the correct part number :( I want to retro fit one to my Merc but don't want to just have a wild punt on eBay and end up with the wrong one...