Yo man, relax, dude. I know it's hot and nasty outside but . .
These guys are right, I don't know what I was thinking. There's nothing to lubricate underneath. The parking (e)brake can rattle or squeak if it's loose.
Here's an interesting thing that happened to me . . a while back, I kept hearing grinding/squeaking noises when I hit bumps, and particularly whenever I made a right turn. Searched underneath for about a month, with no luck figuring out what the hell it could be. One day, I was crawling out from under, and banged my knee against the muffler, and there it was- that squeaking grinding sound. Turns out it was the exhaust system. Even though it was pretty tight and didn't move if I grabbed it, it would sway just slightly enough for the pipes to hit the metal hanger in the middle of the car. But because the sound transferred to the entire section of piping, it was hard to tell where the noise would come from. Whoever installed the exhaust apparently didn't align it correctly, and it was off to the drivers side just a hair. You might wanna check yours out just in case, to rule out this possibility.