One problem related to air bag on-off switch has been reported for the 2005 Infiniti G35. The most recently reported issues are listed below.
The passenger side air bag switch can turn off the air bag when an adult is occupying the seat. I have discussed this with the dealer and was told that this has been a long standing problem with Nissan and Infiniti cars. I am concerned that the air bag will not operate when someone is in the passenger seat.