I had the same problem as well and it was due to me going from a 225/40 18 tyre to a 235/40 18 at the fronts...effectively increasing my overall diameter by 8mm. When I had 225/40 with the same coilover and same height...no scrubbing at all....swap over to 235/40 and it started rubbing the inner plastic guard.
Only scrubs the drivers side inner plastic guard when on full lock going up my driveway and sometimes hard cornering. Also, the more I lowered it the more excessive it would rub, I finally raised it up slightly which decreased it a bit...
not much you can do, I've gotten used to it...best bet is to remove the plastic inner guard if you want...or raise your car slightly to see if it still rubs as much..