I own a 1996 Plymouth Voyager .....
Having the same issues with the popping (clunk) noise.

My struts were recently replaced and a front end alignment performed. The techs also heard the noise and said they checked everything under the front end but could not find anything loose.

HOWEVER! ..
I believe it is my sway bar bushings ...
Not so much the ones at each strut, but the one's bolted to the bottom of the frame of the car. The clunk/pop I am having is one being transmitted from underneath the car's frame to the struts.

CAUTION: Be Safe Doing This Step:
Try driving slowly down a street and steer "left to right" hard and see if you can hear the clunk or pop noise each time you make the turn.

I have not had time to crawl under my car to check on them, however, I do plan on doing it this weekend if weather permits.