The bathroom sink counter is just not enough room for multiple people traveling in Voyager. And the medicine cabinet is very limited as well. Since we do not flush any paper product that we use down the toilet, we keep a small waste basket in the cabinet under the sink. It takes up half of the cabinet space. So not much to store things under the sink. Fortunately, there are plenty of wall space. I was quite surprised at why Winnebago didn't use a larger medicine cabinet as there are plenty of space around it and shelves in the adjacent walls. So I decided to put in extra floating shelves to put more toiletry stuff. The end result was so nice looking and functional.
I decided to add 2 floating shelves as it comes in a pack of 2. One to go next to the sink counter on the wardrobe wall, and one to go above the toilet just below the rear window. One of the 2 shelves comes with a underneath towel rod. The rod was not installed under the shelves on delivery. I first was going to use that for next to the sink counter. So I instlaled the rod under one of the 2 shelves. But then realized that the cabinet door will hit the towel rod when opening. So I decided not to use the towel rod and removed it.
The wardrobe wall is hollow. I first tried using a standard hollow wall anchor, but the anchor was wabbly in the hollow wall that it was not stable to hold the floating shelf tight against the wall. Michael suggested to have a support wood beam in the wardrobe behind the wall. I went to Home Depot and found an 1x2 piece of wood that's in the scrapt pile and asked to cut it down to 22" long. I simply put it in place in the wardrobe and drilled the pilot hole into it from the anchor hole that I did earlier for the hollow wall anchor. Then I got 1-1/2" wood screw that fits the floating shelf holes, and screwed it in through the hollow wall and into the 1x2 wood beam on the other side. The floating shelf uses 2 screws to hold it in place. I then used an L bracket to hold the side of the shelf that's touching the sink counter in place. It's very solid that I can put my heavy tools and drill on it without any wobbling.
For above the toilet, the floating shelf fits perfectly under the window blinds and still allow the toilet seat to come completely up. But the rear wall is different. I'm not able to put a support beam on the other side. So it has to be totally anchored by the rear wall. I found another hollow wall anchor that would work with the rear wall. The rear wall is only about 1" thick. It comsist of thin inner wall panel, a styrofoam insulation, and the outer fiberglass wall. The hollow wall anchor that I found works well as the anchor can dig into the styrofoam and prevent any wobbling. The reviews on the hollow wall anchor was bad because, like the other one that I tried to use on the wardrobe hollow wall, that it spins while trying to put the screw in and it wobbles due to the hollow wall. But with the styrofoam in the rear wall, the anchor works like a charm. It uses an included plastic thin rod to push into the anchor to expand the andhor wings. With the styrofoam in the wall, it requires a bit more force to expand the wing. After a couple of those, the included plastic tool broke. So I continued to use the back end of the drill bit of similar size as the tool inserted into the drill backwards and used it to help push the wings out into the styrofoam. The screw that came with the anchor is 1" long. Since the rear wall is only about 1" thick, I didn't want the screw to go into the outer fiberglass wall. The screw was also slightly small for the floating shelf hanging hole. I used 2 washers to help keep the screw latch the hanging holes of the shelf as well as to keep the screw from touching the outer fiberglass wall. The shelf wobbles slightly as the anchor has a good support layer against the wall and not completely flush with the wall. But it holds. I then added 2 more L brackets under the shelf and anchored to the rear wall the same way and then into the bottom of the shelf. It still gives a bit up and down, but it's not going anywhere.
SODUKU Floating Shelves:
https://www.amazon.com/gp/product/B07KGN1SXF/
1/8" Hollow Wall Pop Anchors
https://www.homedepot.com/p/Hillman-1-8-in-Pop-Toggles-with-Screws-6-Pack-376254/202243046
3/4" Corner Bracket (L brackets)
https://www.homedepot.com/p/Everbilt-3-4-in-Zinc-Plated-Corner-Braces-4-Pack-13542/202950157
1-1/2" Corner Bracket (L brackets)
https://www.homedepot.com/p/Everbilt-1-1-2-in-Zinc-Plated-Corner-Brace-4-Pack-15304/202033892
* I'm not affiliated with any of the links above.
View from inside the wardrobe looking down.