Nice work. On my 2001, I originally had a major problem back there due to the sunroof drain tubes contracting and disconnecting themselves.

But then I had very minor but persistent problems back there. Through extensive troubleshooting, I eventually found that most of the holes in the channel surrounding the rear hatch leaked just a little. Removing and reinstalling with a little silicone caulk made things water tight again.

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2001 X5 3.0i, 203k miles, AT, owned since 2014