Ive been working on the X6 today and carried out some mods ive read about.

If your using AE shocks and springs its worth cutting a short piece from each end of the rear spring, just enough to eliminate the end coils overlapping. I read somewhere that this will allow the spring to sit better and under compression wont rub the shock body.I had the shocks apart and thought why not,I was pleasantly surprised that it works and gives a nice smooth operation.

The other mod was fitting a rear anti roll bar,I bought some of the Schumacher Mi4 mounts U3499 as mentioned on another thread.These will fit without any modification to your car,I used a cap head screw (the same screw as the B4 FT front wheel retainer) and fitted the mounts to the top of the rear toe in bracket.These are great as they come with grub screws with a taper on the end so as to enable you use different thickness bars and adjust accordingly to take out any play which is difficult with the slotted bulkhead method.Happy X6ing!!.