[scottyrocks]

I have had both 15 and 16" (steel) wheels on my '12 and never had any noise issues.

 

[scottyrocks]

I heard everyone saying the same except for the mechanics who inspect and when they don't know what is the issue - they simply say it's due to tire upsize.
The sound is only from the rear-left. If it's coz of upsizing, it should have from all wheels or both left & right rear ends.

Could it be due to my bad camber on the rear-left? Because when I hit a tiny bump, I can feel the hollow humming sound spreading - like when you hit a spanner to the tire and you get a zhommmm... sound. And while driving, whenever I hit an eye-catcher, I could feel the same noise.

This is the first I am reading of acknowledged bad camber on the left. How was this determined? You wrote that the whole suspension was essentially rebuilt, or at least inspected.

This is an extreme long-shot, but were those tires that were placed on the left, directional models that were installed the wrong way?