Front end popping/settling noise when car is parked

If the upper and lower control arm bushings are not preloaded at ride height, which sounds like you have covered, and your alignment is roughed in, I would say your toe is way off, and when you drive it, the tire scrubbing is pulling hard on the tires, either in or out, and it's jacking the suspension, and changing your camber. The tires are being pulled away from where they naturally want to be because they aren't pointing forward when you drive the car. It get exaggerated because as the tires pull away from the centerline of the car, they pull on everything, changing camber, and that changes toe even more. Turn the steering wheel back and forth a few times, and roll the car forwards and back a few feet to get as much preload off the suspension. Measure toe, then measure camber, which you can do by just holding a carpenter's square next to the tire, and measuring the difference from it to the rim on the top, and bottom. The same measurement top and bottom is obviously 0° camber. With a 15" wheel, if the top is leaning in by 1/8", you have 1/2° camber. You can extrapolate that--1/16"=1/4° and 1/4"=1°. I set my cars at 1/16" toe in, as much caster as I can get, which is the front excentric out all the way and the rear all the way in, then turn whichever eccentric I have to so the camber is 1/2° negative. Roll the car fore and aft several feet and check to see if the settings changed. Camber adjustments affect toe. You need the toe close to zero so you don't have that preload when you're settling the suspension, but it has to be the last adjustment you finalize. I don't care what my caster setting actually is because I can't get as much as I would want. If I had to give a number, I'd say 4° positive. I set it to get as much as I can, but being the same side to side is what you really need. If you have the fancy gauges, you turn each wheel 20° to one side, then the other, but you can just turn the steering wheel to one side, say one complete turn of the wheel, check the camber with the carpenter's square noting how much the tire tilts in at top, and record that number for both wheels. You don't need an angle, just the distance in inches. Turn the wheel back to center, and continue so it's turned the same amount in that direction as the previous one. Compare how much the measurements change. The more caster you have, the more they will change. I've never had a problem with cross caster. I've always done my own alignments this way, from 40 year old worn out crap, to rebuilt front ends, to 24 hour endurance road course racecars. Any questions?