OK here is a general how-to for fixing a cowl leak:
1) Go to a NAPA store and get stuff called "glass setting butyl tape". It is in a blue box - part number 4195. Get the 5/16" wide roll. Don't waste your time buying anything else. Trust me, I tried a few things before hand. It's fairly expensive stuff ($15 I think), but there is 15 feet and it is fantastic stuff for lots of applications.
2) Remove the passenger side windshield cowl. Don't forget the screw that is under the little black tab in the middle of the cowl. No need to remove the drivers side cowl. See my mouse thread for some good pictures and info:
Link
3) The water is getting in through your "cabin air filter" on the passenger side of the car. The actual paper filter may or may not be there. You can clearly see how water rolling down the windshield will get into the filter. This is why it has to be sealed. The drivers side cowl is actually not sealed at all.
4) Clean the cowl where the previous sealant was. Also clean the windshield.
5) Put a strip of the new butyl tape on the cowl (not on the windshield) and make sure it seats.
6) Put the cowl back on and press on the butyl tape to get it sealed.
That's it! I think most of those steps are...um...really obvious...but oh well.
I've washed my car thoroughly a few times after I did this and no problems.
Best of luck! [

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