vinegaroon

Unclogging those rear drains can be accomplished by removing the trunk liner on each side. You will then see a plastic tube coming down from the upper fender area. I used the inner part of an old speedometer cable to run upward through that plastic tube. It is flexible but strong. Get one long enough to reach all the way to the roof area. That opened my rear drains and cured my problem. You can put
moderate mounts of water into the sunroof area (not so much that you overflow into the car), and if
those lines are now clear, you will see water drain from those plastic tubes down through a grillwork
in the bottom of the fender wells and out onto the ground. Then you can replace the trunk liner, and go
on your way. Good luck.