Several of my projects have involved the underfloor compartments.  I added a water filtration system, added wiring for computer networking and external satellite dish, and re-arranged the storage drawers for much better storage capacity.
 

Water filtration system:

I started using the water system by merely connecting a hose to the spigot at the campground, running the water through an inline regulator and into the motorhome.  I started trying to place the regulator at the motorhome end, but at one campground my hose started to bulge due to high pressure.  I then placed the regulator on the faucet. 

A couple of problems I ran into was the inline regulator does not have a very good flow rate.  Filling my tank was very slow, and even taking a shower was a system "overload".  The water would start out at a good rate and pressure and gradually slow down as the Foretravel supplied accumulator would lose its pressure.  I decided that a water system overhaul was in order.
 

At an FMCA rally, one of the vendors had a broad line of water products and I said that now was the time to do it right!

I bought a good cartridge filter, a high-flow pressure regulator, several quick-connect fittings, and a 35 foot length of a very high quality hose with a rating of over 200 psi.  I made a simple drop-in / lift-out mount for the filter bracket.  This was simply a small rectangel of aluminum with a spacer plate under each end attached to the back wall of the utility compartment.  The mounting flange of the filter bracket just drops into the slot created by the spacers.  I glued a block of stiff foam below it to support the bottom of the filter housing.

Now, while I am on a trip I keep the hose, filter, and regulator connected.  I put a small shutoff valve on the end of the hose to protect the threads and keep everything clean.  When I pull into a campground I just pull out as much hose as I need, remove the valve, and connect to the water supply.  When we return home, I disconnect the hose, drain it, and connect the ends together to keep it all clean.

This system provides us with clean, oderless water at a good pressure and flow.  Hookup and unhook are quick and easy. 
 
 
 

The filter and regulator are mounted on the back wall of the utility compartment.  During travel, none of these items need to be touched.  The outside shower fixture was changed to one with a swing spout with hose threads.  I can attach the original shower to these threads if I should ever need it.

Compartment storage drawers:

As I received the motorhome, there were two optional storage drawers installed.  There was a large one installed in the main storage compartment on the driver's side.  There was a smaller one on the passenger side over the propane tank.

The problem I had with the larger drawer was that the height of the drawer limited the height of anything I put on the pull-out tray.  This limitation affected the center witdth of the tray for it's full length.  We usually carry an electric scooter for Betty.  It was almost impossible to position it so it would clear the drawer as the tray was pulled out.
 
 

The storage drawer as orignially received was very handy, but severely limited the height of items stored under or behind it.

After some careful measuring, I decided I could remove the small drawer from over the propane tank and replace it with the larger one from the main storage area (with very little clearance in any direction).  I had to drill out the pop rivets that attached the slides to the drawer, and replace them with screws and locknuts after re-mounting the slides.
 

The large drawer fits in place of the small one with less than an inch clearance in any of its three dimensions!

I remounted the smaller drawer in the battery compartment.  I was lucky and was able to hit frame members with all my slide mounting screws.
 

The smaller drawer fits very nicely in the open space over the batteries.  If I ever add a third battery like the U-320's have, I may have to eliminate this drawer.

The final result is truly remarkable.  Without losing any drawer storage volume, I have almost doubled what I can place in the main storage compartment.  Betty's electric scooter will fit almost anywhere I choose to put it.
 
 

The main storage compartment will now hold much more, since I no longer have to leave clearance for the drawer.

Satellilte and network wiring:

Even though I have mounted a satetllite dish on the roof, and use it whenever I can get a clear shot, there are times when there is just no way to get a signal.  For these times I can use an external dish and tripod.  Initially I would unscrew the cable TV wire from the switch and attach it to my satellite receiver.  Now I could attach the dish to the cable jack.  Of course when in a park with cable, I had to reverse the process.

I purchased a second phone/cable plate from Foretravel.  I then modified it to include a Cat-5 network jack in place of the phone jack.  I mounted this just above the original one then ran the wires.  The network wire runs to the same location as the stock phone jack.  I use this network connection when I visit my son, and when the rig is parked in my RV garage.  Both these locations have high speed Intenet access available to me.  Hopefully, more of my friends will get it in the future.  The satellite dish cable runs to the center overhead front cabinet where my receiver is located.
 

I now have 4 connectors for phone, cable, satellite dish, and cat-5 computer.

In addition to these runs, I also ran the phone cable and another network cable across the coach to the base of the dinette table.  I can now connect my computer and have a phone on either side of the coach without having wires in the way.