How does the one for without work? Where did you buy it? And does it still work if I have a drop in bed liner?
Also so i can't just a buy a used bed extender for Titans it has to be a specific one?
The one that works without Utilitrack has 2 brackets that mount just inside the bed near the tailgate cables, and the extender just flips into place when you need it extended and flips back when you don't need it. It's not as useful as the utilitrack version if you need to store it, because you have to just take it off the brackets (it just lifts off) and just set it in the bed near the window, whereas the one with Utilitrack will slide back to the window.
Any of the bed extenders for Nissan Titan should work. Actually, the extender itself is expandable if you mess with it, so you might be able to get ones made for other trucks to work as well. The extender is made by AMP Research, and if you call them they can probably tell you what else might work for the Titan. They're pretty good people - One of the rubber feet came off of my extender, and they sent me a new set free of charge.