Pour some water in the channels,you will see it drain out the bottom if they are not clogged..
Nissan failed there by running the hoses into the framerail/unibody that runs along the rockers.
I saw a thread a LONG time ago about a guy who drilled through and routed the hose out the bottom of the car
Remove the inner apillar trim and kickpanels to see the front drain routing.
Remove the rear inner trim around the rear quarter windows to see the rear hoses.
I have fixed alot of these over the years,from clogs to leaks,and even one that the hose was off from the factory