Rattling/bucking when I decelerate.
 

Okay, so last night when I was driving, I started hearing a *new* scary noise. As I'd downshift to slow down, I'd get this wierd sound, and the car would shimmy really bad. Also, at about 60 mph, the car is just buzzing, it would seem, on the inside. It sounded kind of like the same sound you get when you go over the rumble things near a stop. I think it might be some alignment issues since I found a *new* "speed bump" in the middle of nowhere in a 45 and hit it going 45.

Any thoughts?

Use your brakes to slow down, not your clutch disk. Brake pads are much easier to replace :)

As far as the rumbly thing...Check your tranny mounts, maybe even engine mounts. Jack the car. Check all of your heat shielding under there too...Grab your tie rods, ball joints, etc and make sure you can't wiggle 'em while you're under there....