I would post this in the Nissan Trucks Forum.
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But to answer your question:
The Maxima (and Murano) iPod interface is unique and from what I see cannot be added to another Nissan.
There is an OEM Nissan accessory iPod interface, but it does not have touch screen capabilities. The interface is quite simple with song/album/artist name display and iPod control via the radio's buttons and/or steering wheel controls.
Note: It OEM iPod interface works with most Nissan radio's that has the SAT radio option and/or 6CD changer. These SAT enabled radios have an accessory port that the iPod interface will plug into. If you have a base model radio, it likely does not have SAT radio capabilities and you are out of luck.
The OEM interface is available from the dealer or one of our many site sponsors on the RH sidebar.