I've been hearing a metallic grinding and scraping noise mostly on cold start, at low RPMs, and at low gears. On cold start, it grinds for a few seconds and then eventually goes away. After starting, the noise is worst when I first lightly depress the accelerator, and goes away as I depress it more. I've noticed it gets worse sometimes when I shift from park to reverse or drive, so I have a feeling it's my transmission.
The noise is certainly coming from under the car (not the engine), but after getting underneath, my friend and I could not find the source (the car was already warm at that point). We topped off my transmission fluid, but that didn't change anything; we couldn't find the dipstick to actually check the levels.
Car is an automattic 2003 Saturn L200 with 89,500 miles. I just recently changed the oil. I bought it last July and had a number of parts fail on me, so I'm not confident the previous owner took pristine care of it.
Also, I live in Rochester, NY and so the car had to survive a harsh winter. I had no problems during the winter, however.