general problems of the 2008 Infiniti QX56

On 9-4-2011 I left tallahassee, florida. As I got to the edge of town I noticed it started to idle slightly high. By the time I got to thomasville, georgia, it would accellerate to about 45 mph without any excelleration pressure and the breakes were required frequently. Between thomasville and moultrie, georgia, it would accellerate independently but it would drop down if I pressed and released the accellerator. It also seemed to maintain speed a bit better if I used the cruse control. As I turned onto mack dekle road just south of moultrie, the engine tacked out into the (maximum) red area. In a panic, I pressed the brake and slowed down enough to force it to "park". I restarted the vehicle several times and it revved to maximum rpms. I left it in the lane and called my wife who called ctv towing. After about 30 minutes I started it and it idled normally so I carefully moved it to the the lee lewis road (less traffic and speed). The vehicle was then towed to nappleton infinity in tallahssee, florida on Monday. I called the infinity dealer to tell them it was coming. After running computer checks and test driving, they concluding that the accellerator was hung on the floor mat. That is actually not the case as there was an obvious spontaneous accelleration that started in tallahassee. The floor mat was not moved between the time the vehicle accellerorated on mack dekle road and the time it idled/ran normally to move it to lee lewis road.