To be honest I haven't really given UV exposure any thought. Wouldn't coating the PLA with a rattle can provide sufficient UV protection?
I realised that the images I uploaded earlier were of an early prototype and, true to form, I haven't documented what the latest version looks like. Here is what it looks like in Fusion 360. The model is split in two to fit the build volume of my printer.
Because these housings were designed to fit a 964 housing the backside of the terminals are exposed (the 964 housing provides protection from the elements). It shouldn't take too much effort to design some sort of cover to protect them from any debris the wheels will throw at them.
I'll post the link to Printables once I've uploaded the models.