I have a 2004 6 speed with about 80k. Today, driving home for lunch I heard a thumping sound from the rear of the car. It goes away under acceleration and engine braking, happens when providing maintenance throttle or when I disengage the clutch. Turning left or right doesn't seem to change anything, and it seems to sap a little bit of power. I was able to feel it through the pedals and shifter if I payed really close attention. I am really bad at searching the forum, so I wasn't able to find anything that sounded similar. Does anyone happen to have any ideas on what I should be checking after work today? I'm hoping it's something simple, as this shares daily driver duty with my motorcycle, but I hate riding in the rain, making the timing a bummer. Please, throw out all the ideas!!!