I have a mild rattle, almost like plastic creaking on plastic. I have tried messing with the corner molding, the sun visor, the plastic cover on the left side of the instrument panel. No luck. I also removed the cluster guage just so I could poke around behind it. Still nothing.
The wierd think is... I can't replicate the noise by bangin around. But back out of the drive way and it squeaks away! I received a tip to check the clutch hydraulic line in front of the firewall. I will do that tonight. I also found the side mirror to squeek, but that was easily fixed with spray lube.
Still puzzled.....

 

I have the same rattle, sounded like it was coming from under the dash or the fire wall. On mine it turned out to be the left front fender was loose. Rattled when ever I hit a bump.

 

The pins in my front left fender also weren't popped in all the way. Once a little dirt got in there, it started making a creaking noise.