Hmmmm . .may only be there on the coupe but is not HK dependant as I've removed both setups and the spacer ring is the same.
Just checked the parts disk and it's there on both - described as cover part no. 51418257287 - idenitcal part on both coupe and saloon.
You may want to check it's there and if so, remove it (simple pull off) to allow another 10 mm of mount depth.