For those who are Familiar with Cobb Tuning, they are a very reputable tuner and have had great success with there Accessports best known on the Subaru WRX Sti, they currently make one for the Nissan 350z, They are also coming out with one for the Nissan Titan. Now Mind you they have looked into this and said that Nissan uses a somewhat difficult Protocol to access and would take time to crack into, we all know how picky are ECU's can be. But they said if they can get enough leads for the AP they would do it, or otherwords look into it more,
For more information Cobb Has a Forum, all you gotta do is go on their site and click on the forums, Ive notice a few maxima owners have brought the maxima to their attention, a word on the street is that they are trying to come up with a AP for the 09 not to sure though, But I will post up a Dyno Graph of a Nissan 350z for you to see the gains it gets with the AP. they also currently make one for the GTR, they has seen some really great improvement with the AP.
Here is a link to there site,
http://cobbtuning.com/products/?id=3686
also like I mention before they have a forum just tell them that you would be more then interested in sending them your car for testing I would be all for this.
They've also mention they would love to come with a AP for all Nissan Vehicle's. they are very big with Mitsubishi and Subaru Like I mention before, also Mazda. with their Speed3