Blocked drains can lead to expensive problems, that is why I often look at the drains on each side of the car for debris. Any thing I see I try and remove with those four jaw retrieving tools which also have magnet on the end. I just carefully poke it through those rubber combs at each end of the cowel.

Another little tip to remember, I wanted to run some wires through to the trunk. So I taped them to the auto transmission dip stick and poked it through the opening in the bulkhead. They went exactly where I wanted them to go, easier than trying to poke limp wires through.