The first panel I added was on the driver side. I used a 200watt panel from Newpowa. Being power hungry as we are these days I then removed the passenger side rear Zamp 100 panel. To do this you will need a heat gun to loosen the caulk. Each of the mounting feet on the zamp panels have at least one screw. Once the caulk is removed the screws are worthless and will pull right out. To seal the mounting holes I filled each hole with Dicor lap seal. After this had cured some I applied Eternabond tape over. On the passenger side I used a 180 watt panel. The choice to use a 180watt panel was because it was shorter allowing more area at the top of the ladder.
To affix the new panels I used 3M VHB to the mounting feet, Be sure to pre-clean the mounting surfaces. Then each of the mounting feet were covered with Dicor self leveling. This has provided a total of 480 watts of solar. The original Zamp ZS-30A controller will handle 510 watts, no need to change it. To adapt the new panels to the Zamp receptacle box on your roof you will need this cable and adapter.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1. Zamp wiring is backwards.
In two years we rarely run the generator unless its a dark day.
Oh and the 100 watt Zamp panel that we removed later became my power source when the rig is covered for the winter months. On my Navion there is a solar receptacle in the back of your power bay. I mounted the Zamp panel on some 2 x 12 x 30" boards placing it on the cover above one of the new larger panels. Worked great keeping the batteries fresh thru the winter that is until we had a wind storm toss the panel about 100 ft across the yard. The cover was torn off too. There are some very heavy concrete blocks near by that I will be mounting a panel to this winter to keep the power going.