That’s a great point — I’ll definitely have the battery tested for CCA instead of just relying on voltage. Makes sense that low current under load could trigger those random electronic errors. Thanks for the tip and the link!
Problem solved. Someone mention checking the nuts that tighten the license plate in the back. They were tight but left space for the lower part of the plate to move freely. I replaced the nuts for others bought at an auto part store. It was actually the license plate's lower part flying freely with speed and making the noise. Nuts replaced, license plate cannot move anymore. The noise is gone.
Problem solved. Someone mention checking the nuts that tighten the license plate in the back. They were tight but left space for the lower part of the plate to move freely. I replaced the nuts for others bought at an auto part store. It was actually the license plate's lower part flying freely with speed and making the noise. Nuts replaced, license plate cannot move anymore. The noise is gone.
I am old fashioned. I know manufacturing techniques are better today, but when I bought my Edge straight from the dealer, I had the engine oil changed at 1,000 miles and the transmission fluid completely flushed at 15,000 miles (my Edge is not AWD so no differential or I would have also changed it early.)
It is bad rubber molding The crap just falls apart due to UV and heat.
I know as I have an 08 Limited. At 1st it was an air leak I fixed with a length
of vacuum line to hold the window in and stop the air leak. (Driver's side)
If the noise you're hearing is coming from the back of the dealer, check for a TSB that applies to the rear differential. Not sure if that's where your sound is coming from, but I do know there were some issues with improper oil levels or something similar that lead to failure. The differential on my GF's vehicle was replaced when the dealer took delivery of it (used), so I'm assuming it was on the way out.
To get your answer, a simple internet search will answer your question.
However, to repair the sunshade, you are going to have to remove the glass panel. Are you up to the task?
First question that pops to mind: Are you cleaning your rubber moulding with anything? Any kind of chemicals, just water, windex, etc.? Anything at all?
Something you are using may be degrading the moulding.