As long as I have even tire wear and no handling issues, I'll let it go. But like I mentioned, the last alignment resulted in the right hand side having 0.4 degrees more negative camber than the left, so I may not be that far away from a replacement of the lower bushing. I figure that will be the best time to isolate the squeak. Hey, at least it's not an electrical problem, right!

2002 X5 3.0 242,000 miles
2004 325i 107,000 miles