So I had this same problem and yes it can be caused by a kink in the drain lines, but I think more times than not, water leakage is due to poor design of the sunroof assembly.



Heavy rain and a crappy seal around the sunroof glass will still cause water leaks.


The sunroof mechanism is not designed very well as there is only a small area that actually catches water to divert it to the drains. It is not well protected for larger volumes of water.



For example, if you pour water on the silver run channel (I will try to post a picture later), the water will actually run down the channel and over the sunroof assembly (and drainage area) onto the roof liner, which then makes its way down the A pillar, and into your glove box and footwell area.



Try it for yourself, just be ready with a bucket.


Take off the A pillar and position a bucket on the edge of the seat between the dash. Carefully pour water into the drainage area where you see the drainage hole. You will notice that no water will come out of the headliner. Now pour water vigorously over the entire area (or overfill the drainage area), and you will experience the water draining from the headliner where it meets the A pillar trim... this is why you get water in your footwell because it drains down the A pillar.