There are all kinds of ways water can get inside on the convertible.
If it only happens with high volume rain and from that front leading edge of a window I would look at adjustment of the window. No biggie, over time they seem to settle in a bit. It only takes .5mm to let some water in.
Here are a few pics from one of the last adjustments I did.
cmesurf wrote:
There's an ITB10-070 November 11,2010. 2009 – 2011 G37 CONVERTIBLE; WATER LEAK AT WINDSHIELD HEADER to fix this issues.
Good find,
I think that one requires the water to be leaking from the seal. It's the type of thing you would know if you saw it.