Having some fun yesterday I found the car quite sensitive to rear rebound damping on the short Rob Roy hillclimb circuit.
There is a section that will heavily compress the suspension just before a sweeping uphill (with crest) left hand bend.
With 5 extra clicks of rebound the driver (me) ran out of talent and rotated onto the grass.
With that reduced to only 2 extra clicks I took more than 1 second from my previous best on a short 650metre run.
Unfortunately I didn't have the video running for the half spin but looking at other runs I suspect the suspension wasn't recovering from the compression before being loaded up again on the bend (with some bumps).
I spoke with the Group S class record holder (very quick S2) and he recommended running the rear quite soft at the rear with minimal rebound (which is actually where I started).
He also suggested a heavy front roll bar (but himself didn't run a rear roll bar).
Basically has that setup on his new Europa T/C (or might be a Special) that is already running quicker than his old S2.