Creaking sound under the driver's compartment
 

Hi... I have an 06 G35 Coupe with 62,000. Recently it developed a creaking sound that, to the best of my ability to tell, sounds like it's coming from under the left side of the car. Someone suggested it might be the rubber seals drying out around the driver's door but I can drive with the door open (holding on to it) and still hear it... If I move at say 10 miles per hour and then hit the brakes reasonably hard, as the car stops you hear this creaking sound that would appear to be coming from somehwere under the car below the driver's door... I can also make it make this same creaking sound if I roll up and down the entry to my sloped driveway.

I've read several other posts here about creaking sounds in the front end of the car but this is clearly coming from the middle of the car on the left side, more or less right under the driver's seat and maybe even a little bit more toward the back...

Does anyone have any ideas of what might be causing this creaking sound??? Any help would be much appreciate... thanks... bob...