[ebruner]

So... mystery solved. On the 2013 135is, the rear roof drains tie in with the misc trunk drains and trunk sill drains and exit just behind the rear wheels. They come out of the two 90 degree elbow drains that are just behind the wheel liners.

Mine were draining a bit slow, but still functioning. Now onto other sources of said water leak. my money is on door vapor barrier.

However for posterity sake, the drains on this particular car are on both sides of the moon roof and exit just behind the rear wheels.