Large thuump noise developed around 8000 miles on automatic tranmission of my 2004 350Z. It has been taken to 2 dealers. Both say it is perfectly normal. We test drove 4 other 350Z's and none of them to what my car does. The dealer refuses to fix it and Nissan Corp. Says they will help, but continue to ignore my calls and hang up on me.

- Miami, FL, USA

I purchased a 2004 Nissan 350Z on 3/31/04. Since then the transmission has, on several occasions, gone into what the manufacturer calls "fail safe" mode, which means that if it detects a problem it will immeiately and without warning slam down from whatever gear you are in to first gear. This has happened to us on a highway twice, and the car came to a sreeching halt, nearly casuing an accidant. The car went from 5th gear to 1st without warning to us or to those behind us, and it did this suddenly, bringing the car to a virtual halt as if the brakes locked. The manufacturer has been unresponsive, and the dealer says that this is a deliberate design in the transmission and cannot be changed, and it kicks in even if the "error" it detects is false. This dangerous design is in all of these cars(automatics) and is inherently dangerous, especially as it seems to happen at high speeds on the highway and there is no warning to us or the car behind us.

- New York, NY, USA