I'm trying to narrow down the source of this squeaking before I take it to the shop, so, I thought I'd do some fishing.
If I drive with the left side windows down, there is definitely a squeaking from the rear end.
The ONLY way this squeaking changes tone or frequency is when the car changes speed.
It does NOT change when increasing/decreasing engine speed, or braking, or taking the clutch out/in.
It does NOT show up, or change when hitting speed bumps or heaves in the road, like bushings or the like.
Some of my gearhead friends think it's a bad bearing. My mechanic hasn't heard it, yet, but he says bad bearings don't squeak, they drone then start to "roar", the worse they get.
What do you folks think? Is there some sort of heatshield back there?
Any advice would be welcome.