BALL JOINTS, BALL JOINTS, Ball joints!,
sorry ive only heard this noise from 3 of my own mn12's and ended up replacing upper and lower ball joints on all of them.
it was making the noise on all 3 cars,
my 96 was making it, all the boots looked good etc, but one broke while it was making that noise one day, glad i was only going 1 mph instead of 50
well the 97 that we used to have also made that noise so i just went ahead and replaced them too.
then the beater 90 i had last winter, one ball joint was already replaced when i bought it, so i replaced the other side lower ball joint, took care of the noise for about a week and ended up doing upper ball joints.