I have a 2005 S350...lately Ive noticed a strange noise. I hear a humming noise while driving at moderate speeds and the sound builds up while Im driving. Once I slow down or stop completely, the humming sound stops and I hear a very noticeable air release sound from the front of the car. It sounds like the air brakes on a truck. This started to happen after I had my right front suspension strut replaced. I have no warning messages, the air magic suspension seems to work absolutely fine otherwise. ANy idea what this is?

The humming is your airmatic pump filling the system after the air is being released . Clearly there is some problem why the air is releasing when you stop , if the issue started right after you changed the strut either something wrong was done during install or the part is defective