Before jumping into subframe mounts, have you looked at the lower control arms? These are known to "clunk" when the bushings get worn. Easy change since you can buy the entire arm with ball joint installed.

If it is indeed a subframe mount, you should be able to drop the rear of the cradle and sneak them out. Search the forum here and see what you can find. If you can't find anything on it let us know. Sometimes the search sucks, lol.