Todd... One thing that will improve the operation of any end fed antenna is to improve the RF ground. I'm sure you are grounded for 60hz AC safety, but an RF ground will involve lots of capacitance to earth. First, tie the ground lug on your RV frame into your ground system. The metal skin of most RVs is generally a mess of enameled unconnected sheets, so don't depend on it. Drive a rod into the ground, even if it's only a four footer. This makes a handy common point. Then go to the farm store and get a length of welded wire fence....maybe 4 feet high by whatever length will fit under your RV. It's actually wide enough for a pair side by each under there. Solder pigtails onto these and connect them to the system. You now have a stealth counterpoise.
I have used this method under an RV with good result, and I use critter fence ...longer lengths...under my 160m vertical at home with good results. Just make sure it's galvanized after fabrication. Most common chicken wire is not, and will corrode in many environments.
Any end fed antenna is only half an antenna. You have to help it out with the other half.
73 de Norm W1ITT