thank you everyone. You all may be right about the springs, the car was in for alignment a day or two before so it's possible when they lowered it off the lift the springs weren't seated properly. Surprised it would take 6 or 7 miles of driving for them to "pop" into place but I suppose that is possible, especially since it happened on both sides independently.
That first "SNAP!" was right next to me and scared the bejesus out of me LOL!! I half expected to be covered in smoke and sitting in a puddle of
oil.
In any case, I checked and the springs are currently seated properly. Will take the car out for a test drive later this weekend and see if I can reproduce the sound (hopefully NOT!)