I am a fellow Nissan owner - but I drive a Murano and hang out on Nissan Murano .ORG. I am helping a friend out with some projects on his Frontier though - so I am coming to the experts for guidance!
Nothing fancy - I just did a tight iPod integration in my Murano, and he wants me to do the same in his Frontier. Doesn't look like there is any option but the factory though unless we replace the head unit.