Just a FYI. I installed Super Cub X from FSAddons into the Prepar3D v4 Add-ons directory and added an appropriate add-on.xml file and all works without any changes in P3D 4.0. I like this addon purely because of the variation of models you get.. the flight model is not the best and neither are the VC graphics however it's nice to fly around with tundra tyres or skis. No issues were found, all gauges and sound work as it is a relatively basic aircraft.

FYI here is the add-on.xml file contents:

<SimBase.Document Type="AddOnXml" version="4,0" id="add-on">	
	<AddOn.Name>FSAddon Super Cub X</AddOn.Name>
	<AddOn.Description>FSAddon Aircraft Super Cub X.</AddOn.Description>
	<AddOn.Component>
        	<Category>SimObjects</Category>
        	<Path>SimObjects\Airplanes</Path>
	</AddOn.Component>	
</SimBase.Document>

 

 

Even simpler: point the installer to your v4 folder. Works ok: gauges, textures and handling.

Cheers