We have a 2005 8356 with the same bathroom as yours. We went to dollar store, bought the self adhesive, round furniture felt (about 1 1/2 inch circle) put it on the vanity side, and that is where it has been for 2 years. Those lil felt pads come in handy in more places than you can imagine, and they come in many sizes!
2006 Crescendo 8356DP C-7 Cat, Freightliner Chassis
Suck, squeeze, bang, blow...Down the road we will go