Mines booked in on Monday to have this same problem looked at.

The symptoms I have, are a car that tilts to the left (at the back) when parked. There's a very noticable hissing soud when I pull up and walk away from the car which is - I assume - the airbag losing all of its pressure. Then, usually after a minute or so of driving, I get the SELFLEVEL SUSP.INACT message. Sometimes, (usually on motorway driving), I dont get the message - wierd.

So far, I haven't noticed any difference in ride or handling. I asssume the compressor is working double time to keep the bag inflated. I called my local dealer and asked them if they had a rear suspension air-bag (on the advice of this forum as this was probably leaking. They have supplied me with the part - 37.12.1.095.579 at around $200

Which is part 1 in the followowing diagram....



Only thing is, I have a feeling I may actually need part 5 - the reservoir. It's no problem - as they will take the air spring back if thats not needed.

Part 5. 37126755021 doesn't come up with a price.

If anyone could advise on which one is commonly referred to as the 'airbag' I would be grateful.

Probably find out on monday that its not the part I went and bought - and the other part has to come from Germany ...

Although the car drives fine, I have a feeling the prolonged use will cause part 8 to fail (the compressor) and thats $800 !

I'll keep you posted on how things go on Monday...

Cheers.

Kev