I did notice the orientation of the nipple when I researched this. I'd only get the OEM ones anyway. Luckily no road salts here in Florida, so no rust!

Yep, SimplySpeaker refoam kits. I'll have to check the speaker I replaced to see if it's indeed subtly torn. I think one of the other speakers is about to go bad. I need to see if there's some kind of test noise CD that plays tones to each of the "corners" of the speaker system to locate a bad speaker. I've changed the front/back left/right sound settings, but I figure there's got to be something like that somewhere.

 

@StanVanDam

Dont see a heat shield anywhere in the link?

 

The exhaust heat shields are so easy to find, you don't need a link. Just put your head under the car, even without any lifting, and look at the exhaust pipes - you'll see the shields. The OEM heatshield clamps are just clipped on - not a worm gear clamp. If they were rusted like mine, you can easily rip them off with your hands. Otherwise, pry or cut the clamps off with pliers or wire cutters, pry the heatshields off and scrap them. Obviously don't go near the exhaust if your car has recently been running, you could burn yourself. If you have air suspension, raising vehicle height to HIGH gives you some more ground clearance to slide underneath the car.

 

UPDATE!

So after changing the LCA bushings, both wheel hub/bearings, we finally found the culprit: upper control arm ball joint. I got the left one replaced at my indie shop, and no more rattles. For completeness, I'll be replacing the right side UCA myself in a few days. Whew!

 

Did you replace the entire upper control arm? OEM or aftermarket part? Sounds like I have the same problem on my '06 ls430.

 

That sounds strangely familiar.