Hi guys,
Haven't posted for a long while....
It's a long shot, but might worth having a look.
What are you storing in the storage compartment under the headunit?
My 42,000km 20-month-old Kizashi had a buzzing rattle that's been bothering me since the 3rd month or so. It sounded like it's coming from the area where the dash meets the windscreen. Sometimes, it seemed it was from the air vents. Sometimes, the dash speaker cover. Where ever it was, it did't sound like it was from the storage compartment. It rattled according to the acceleration/deceleration of the car. Say, it's quiet when I was cruising along but when I hit the brakes to gradually slow down, it buzzed. Sometimes, it's the other way round, buzzing when moving and no buzz when braking.
I couldn't be stuffed asking the dealer to look at it, because I know they are just going to take off the dash, and that has the potential of creating more rattles or issues.
On day one, I mounted a TomTom GPS unit in the storage compartment. I stuck a plastic sheet using double sided tape in there to hold the suction cup of the GPS unit. Recently, I put my hand in there to fiddle with it and the rattling stopped. Came back the next day, and I pressed the plastic sheet hard against the wall and it stopped.
So, I removed the whole assembly, replaced the plastic sheet with a heap of rubber non slip pads, and so far so good.... no rattle or buzz.
My theory is that the rattling plastic sheet at the back of the compartment must have travelled through the back of the dash and ended up sounding like it's coming from the windscreen. Acoustic source inside a car can be hard to pin point.
Clear out everything inside the car and see if it helps.
I hope this helps. Good luck!!!