so recently had the Airmatic malfunction light come on my 2012 E63 AMG, it’s sporadic and I do notice the typical hissing noise not just after parking but while idle for a while. I do not notice any sagging and the suspension seems to rise properly. Mercedes dealer diagnosed it as “contaminated water” in the system and must be replaced. quoted $5000 to replace it. I’ll be getting a second opinion from a euro shop in Charlotte next week but wanted to see if anyone had a similar experience / recommendations etc.