Also, I think dkwilfert's comment isn't about the leak originating at the A-pillar. There's a trim strip running across the roof, just inboard from the doors. Underneath that is a seam where the steel roof meets the steel side of the car. I think that's where he's talking about the leak originating. Then once the water gets inside, it runs downhill & you don't see it until it gets to the A-pillar.

Watch from the inside with the doors closed. Have someone pour a little water into that channel under the trim strip. But don't use so much water that it pours all over everywhere on the outside of the car.

 

You are correct, I was stating that the leak may be on the roof and once the water is INSIDE the car running down the A-pillar. Also as stated, this is a COMMON problem on the Odyssey, and the Accord and Odyssey are both made in the USA though at different plants. Not unreasonable Honda would use the same body sealant at both plants, and it isn't as common on the Accord since it has less body flex than the van.

 

This is a link to a Honda service bulletin regard the 2003 Accord; but, the procedures are similar.

https://www.driveaccord.net/attachme...-037-pdf.5402/

 

Did you ever find the source of the leak? My 08 Accord (with sunroof) is leaking rainwater in the exact same location inside the car. Coming down from the drivers side dash right near the lever to pop the hood, and dripping onto my speaker. I’ve tested the drain holes on the sunroof and they appear to drain water fine. Please help!