One problem related to engine belts and pulleys has been reported for the 2006 Infiniti G35. The most recently reported issues are listed below.
I have a 2006 Infiniti G35 sedan. After I purchased the car. I noticed that there was noise coming from the cars belt during cold start. I took it to the dealer they said it was the belts. I got them changed. Its is still making noise. I have been on other forum sites and other people have the same problem. For some people the noise lasts a few seconds for other couple of minutes. I have always called Infiniti and told them about the problem. It is not only the 2006 that have them, its is the 2003,2004,2005 and 2006 from what I have heard.