clogged drains, google it, it's a 5 minute fix.

Every time it rains, I am suddenly getting water in the back of my XC90. I did some research and it appears this is a problem in this year's (2017) model, and appears to be going through the sunroof. No clue what could have caused it! So freaking annoying - anyone else had this issue? It seems like Volvo not owning up to the defect.