[s-cars] Creaking rear suspension - thoughts?

[Dave Ellis]

About four weeks ago I had new Eibach/Boge springs and dampers installed 
on my '93 S4.  Over the last five days a creaking noise has developed 
from the rear and is getting more pronounced by the day. 

It is most noticable at low speed but I suspect it's there all the time, 
just covered by road noise.  Standing outside of the car as someone 
gets in or out I can hear what I suspect are the springs creaking quite 
clearly.

A quick search of the archive turned up a few others asking about rear 
creaking after installing Eibach springs in 2003, but there were no 
solutions posted I could locate.

Does anyone happen to know the solution?  At the moment the most 
promising lead seems to be a reference to front H&R springs creaking 
due to a rubber sheathing around the spring coils.  The rear Eibach 
springs I have also came with a rubber sheathing around three or four 
coils, and I'm wondering if perhaps this is the culprit.  The creaking 
noise started shortly after driving on a dusty dirt road, but this may 
just be coincidence.

Any collective wisdom regarding this problem?

Thanks!
-Dave

'93 S4
'99.5 A4 1.8t