What Anchors to Use for Interior Walls?

Try to find the wall studs. However. some have only metal studs, and they are also hard to anchor to. Even if they are wood, the spacing is probably wrong for what you need.
We added a fold-down shelf to a wall that backed to the bathroom sink and the cabinet under it. I drilled all the way through, and put a plywood backer board on the wall inside the cabinet. Then bolts holding the shelf all the way through, with nuts and washers inside the cabinet our of sight.
Consider shelves with legs to the floor, anchored to whatever wall studs you can find. Maybe a wall anchor into the wall paneling to stabalize, but not to support weight. Good Luck!!

I had a C class and wanted to add a LCD TV to the storage area for a exterior entertainment center of my SOLD Four winds 25C. It had a huge rear storage area and the TV would be on a swivel arm that could extend about 1 foot from the wall it was a 22'' TV but still pretty heavy especially extended from a foot out from the wall. I use a 2'x 1.5' piece of 1/2'' ply wood screwed in to the back side of the wall where I wanted to mount the TV. Did a very good job, held up to road vibrations and was very sturdy.