I wanted to replace the shower faucet in our 2020 Pace Arrow LXE 38K but could not find a way to access the hot and cold water connections behind the shower.  There's no obvious access panel inside or outside.  I searched the internet and posted in several RV forums without success.  Several responses said they had to cut through the rear closet which I was unwilling to do.  Then someone suggested I look behind the large piece of trim on the other side of the shower wall inside the bedroom. Turns out the trim piece is just held on with a few 24-gauge brads.  Sure enough, there's a nice cutout that makes it all easy.  Thought I would pass this along.