Water on the back seat floor passenger side after a rain

What is your question?

After heavy rains, the passenger side back seat floor gets 2 - 4 inches of water. I have had the sunroof drains cleaned as well as the drain for the A/C. Could it be the seals on the sunroof/moonroof need replaced? What would the costs be

What makes this problem better or worse?

worse during heavy rains

How long has your 2004 BMW 525i had this problem?

4 months