 My car makes a loud noise & there is vibration in the front of the car when the car is accelerated. I brought the car in to the dealer lots of times for a period of over 3 months.  They said I needed to replace the entire exhaust system. I paid to replace it but it didn't fix the problem. They then replaced the catalytic converters, fuel rails, engine mounts, adjusted the front cradle and finally the transmission.  They couldn't fix the problem & Nissan corporation told me after replacing all those items on the quest, that the vibration & noise was normal for this vehicle & to just deal with the problem.  Nissan acknowledge the car had a problem in the beginning, now they don't want to help. 