We have a 2015 X23B and added a medicine cabinet just last month. We went through the dealer and had them order the part for us. The key was finding a unit that had the medicine cabinet we wanted and using the VIN from that unit to order the cabinet. We used this VIN - 1UJBJHBJ9G1JH0139. If you have your dealer order a medicine cabinet for that unit you will get what's pictured below. My dealer said there is no one part number for the cabinet, its many individual part numbers that make up the assembly. Cost for the cabinet with shipping was $110. I had the dealer install it since I was bringing it in any way for warranty work so I don't have any advice for installation. Dealer charged me $40 to mount it so $150 total cost. To us that was worth it since the lack of bathroom storage was becoming a problem for us. If your dealer has problems ordering tell them to talk to Julia at Freedom RV in Slinger, WI.