DD Trooper Rainfly?

I have a Zuca Cart that I use for most rounds, but there are times where I play a course where the cart won't work (mountainous, thick forest, etc...) in which case I have a DD Trooper bag. I've been looking for a rainfly for the DD Trooper but I don't see one, am I just missing something? What alternatives do people use if there is no specific rainfly for the Trooper?