Noticed the same noise as the O P described. Looked at the upper strut mounts and found brown crumbling material on both sides. Driver side is much worse. Something obviously wrong here. As the fender is pushed up and down it looks like the center shaft of the strut stays in place and doesn't move with the body.
Purchased the car from a Lexus dealer with a 90 day/3000 mile warranty which is still in effect. How much does this cost to fix. Looks like the strut has to be removed to replace the part. What ever it is.

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