I scored one of these valves through my warehouse, Peterbilt warehouse go figure, at about $30. Haven't installed it yet but will this spring. What it does it replaces your oil pan drain plug with a ball valve that opens with the flick of a small handle. The part number is F103 for all Nissans 1990-on. Here's a link to their homepage.
http://www.fumotousa.com/
A lot of my fleet clients use these and I have had no complaints to date, let's see how I fair with one.