Water leak in passenger footwell

[awolfinsheepsclothes]

As the title suggests I have a leak in the passenger footwell that I sometimes find under the carpet. So I lift the carpet and let it dry and it doesn’t reappear. So I didn’t think it was that bad, I was wrong it’s all under the rear passenger side carpet! So I’ve removed the seats to let it dry out. I’ve done the usual suspects
Botangs hole
sunroof drains
Aircon drains
scuttle outer and centre
Have I missed any? But I suspect I have the earlier foam seal between the ecu plenum chamber and the bulkhead,
Does anybody know the part number for the later rubber seal that IT Ian has mentioned in the past. I can’t find it in Vagcat maybe I’m in the wrong section