Sorry if it is commonly known, but I decided to share it...
I had water under dash after rain. Left hand side, on wiring harness, next to the cardboard side cover panel. I sent my mechanic under dash and I was pouring water from the bucket: on the wiper shafts and then along the windshield seal. And we found it: water was going down through the hole for windshield washer hose, along the washer hose down to the other hole for this hose under dash, onto the wiring harness, to the left and down on the cardboard panel.
I figured there should have been two sealing grommets on that washer hose - up there, next to the air vent flap as well as down there, under dash (the washer hose goes from the pump, through the firewall (grommet with hood cable), up through one hole under dash, up through another hole next to flap and to the nozzle).
I did not have those sealing grommets. In some cars they might have deteriorated and perished and now are leaking water.
That is why I thought I would write this - maybe will help someone locate an annoying leakage.
