Also, I would like to know what kind of travel you have, and what your spring rates are.
You stated that the car is dropped 1.6" - how much travel do you have past that point, in compression?
Are you using the OEM style, or Eibach/FRPP bump stops? If so, how tall are they?
I just don't see how this is happening. On our car, dropped 1.50" - we have a ton of room between the axle mount and the chassis.
There's a whole thread of every mod I've done.
ST XTA coilovers, KW doesn't publish and wont tell me over the phone the rear spring rates because the rears are progressive.
The standard coil-over bump stops, oem ones removed.
Not sure why the bump stops are even a concern, I've had them on for a month with daily duty and have only have bottoming out "wham!" incidents since putting the Watts on yesterday.