bad vibration when accelerating

98 aurora with 157,000 miles on it. have had basically no serious problems. till now. when accelerating car vibrates really bad. when at highway speeds car will vibrate when giving a little throttle. when shifting from park to reverse or from reverse to drive seems to be a clunking sound under car. at speed if i just tap the gas there seems to be a clunking sound under car. any thought would be greatly appreciated. i really love this car.:banghead:

From this desk tough to diagnose noises. Bad axle joints come to mind. Possible bad motor or trans mounts, someone has to listen to this on site to tell what's what.