The windshield noise doesn't occur as reliably as the rear deck noise so it's harder to determine whether an attempt to silence it is successful. This noise would occur mainly in cold weather and I took advantage of some low temperatures last week to run some experiments.
I followed most of the TSB that suggested trimming the windshield clips but stopped short because I didn't believe it was the source of the noise in the TCH.
It seems that, at least in my car, the dash has some vertical play in it that was perceptible when pushing down on it. The windshield, on the other hand, would not budge even when I put all my weight on it.
I decided to insert shims between the windshield and dash. I started with paperboard and it didn't even come close to fitting in the gap. Next, I cut several strips of corrugated cardboard. They were intentionally long so I could easily insert and remove them while driving. As you can see from the picture, the gap is big enough that it required two pieces in some areas.
The noise never recurred and I eventually left only the center shim to be replaced by something shorter that will not be visible.
From my observations, I concluded that the noise is from the dash bottoming out and not from hitting the windshield. The windshield is only involved in placing a shim which puts pressure on the top of the dash and prevents it from moving vertically. The dash is basically preloaded so it stays bottomed out instead of bouncing up & down minutely, creating noise.
In conclusion, the noise appears to be gone but it will take more driving during cold weather to be certain. The next step is to create an unobtrusive shim. I will also look into easy methods of removing the dash and fixing the problem at its source.
Windshield/dash noise findings
