When I installed my Koni's I was at stock height. Then I lowered the car and the shop didn't trim the bump stops. When I found out I trimmed them myself and it was obvious that they had never hit the bump stops. In other words, if you don't have the rear ones you should be ok without them until you can find some. The trimming should be more or less equal to the drop of the car. My instructions were to trim 30 mm if I remember correctly. Look at the pictures in the suspension extravaganza to know how much. Woody also has a thread somewhere.

Les