I was on my last lap of the evening when a very disturbing sound began to emit from the rear of my car. It's a very systematic sound, almost a "clang". When I accelerate the sound gets quieter, and when I am off the throttle the sound get louder. I can feel the clang in the shifter, and if I move off slowly I can feel the clang in the clutch pedal. At around 100km the sound is not so bad, and of course the sound gets faster as you accelerate. No fluids leaked, and other then the noise and sensations through the shifter, you don't really feel that anything is wrong. I was thinking it might be either drive shaft (CV joint?), or something wrong with the diff? The gears shift fine, and the clutch feels fine as well, so I am pretty sure it's not either one of those. Any ideas?

 

Is your car a Buick LeSabre, a Hyundai Pony, or a Porsche?... the model/year would help as well.