Put some good miles on the car yesterday. Drove about 35 miles one way down to the Houston Galleria. I had the AC on and radio up and was mostly in 5th gear. I got in to traffic in the galleria rolled down the windows, killed the AC and turned down the radio. As I pulled away from a light and let out the clutch I heard squeelish moaning creak. Sounded like the throwout bearing perhaps. This did not happen before my entire chassis teardown and overhaul last summer and it didn't do it before I changed over to Redline MT fluid this last weekend. However I never have really driven the car that far since I have owned it. I got back about 11 last night and as I eased in to the driveway it did it again. I backed out of the drive to listen again and it seemed to be worse with more load on the engine. It almost sound like it is coming from the rear end somewhat. The farthest I usually drive is about 5 miles in the car so I am not sure if it took it really getting warmed up to make the noise or something else is going on. I did notice a few months ago, a "whirring" noise from the trans or rear end that would cease when I depressed the clutch. Not sure if something is getting worse or something else has popped up.

A creak sound is more likely from urethane bushings. A whirring sound is more likely a throwout bearing or just a normal trans/engine noise.

A whirring noise that stops when you push in the clutch is probably an input or countershaft bearing. The 280Z 5-speed in my Z does the same thing, as does my S2000. You'll hear a lot of things in a car with little to no sound insulation.