I think I have the same problem as well - I have all the same shake/vibration characteristics only I've noticed a few more things. Mine seems to do it only after I've throttled heavily (passing a car between 50-75 MPH), and if I apply the brakes while the car is vibrating, it amplifies the vibrations. Also, when I am at a standstill and shift into DRIVE or REVERSE, there is an audible "clunk" from the engine bay. That same clunk happens if I am driving straight in 1st and hit the gas after releasing it (jerking action). Does anyone agree with me that it could be an engine mount? I thought it might have been a CV joint but that would make noise while turning and my car doesn't do that. Am I right? B.T.W. my car is '97 LX V6 ATX. Any help would be greatly appreciated,
Chad