I thought about this alignment going out of range issue all over again and thought that something else might be wrong. Indeed today I noticed that when the front wheels are turned to one side, the inner wheel (e.g. left wheel when turning left) goes into positive camber very significantly, to the point where the inner edge of the tire is not touching the ground (when the car is stationary). The outer wheel seems ok, when observed with my untrained eyes. What's the problem here?

I think this is the reason why the front tires are wearing out badly in the outer edge.

Thank you very much for all the help.

Ying