ok... the picture thing doesnt work for me... *sigh* well the pic is in my album... guess ill change it to a link... http://priuschat.com/forums/album_pic.php?pic_id=717
ok I had a look and it seem that the split is to far over to the driver side of the engine compt. if you look at the passanger side of the car (from the front) you can see in a really heavy rain or a car wash if you get the water over the top of the seal it lands right on top of the valve cover and will fill the spark plug tubes. So what I think their doing is to put the foam on the hood where it meets the current seal and blocks that path for the water to go.
just had another look and it looks like that if the seals meet and do thier job the drains in the cowl cover can probably handle the flow. Just can't stop the splash over. The drains take the water down the front of the metal cowl and behind the motor and wiring and relay panel.