Done the deed. Got the new car home only to find front brake pads need replacing. Went searching for the Locking nut key. Absent, spent the last 2 days chasing dealer for it. No sense of urgency. Went to the local merc dealer who had a special box of master keys, some sweet talking and hey presto 10 minutes later a replacement was on order. It would appear they have 2 sets of masters. We need the 'old' type set.