OK, this was an older post but I'll update.
After I finally received the SnapVents I ordered, it turned out aviation plexiglass is about .030" THINNER than the plastic windscreen on the Signature Honda. I called the manufacture in Knoxville and they said DO NOT INSTALL, IT WON'T WORK, so I threw them in the "bad idea box" in the shop.
Fast forward to yesterday...I came back looking like a "concrete worker" (LOL, remember that one??) and said "FUGG IT", I'm going to look closer at these vents.
Turns out that with VERY little massaging with a file and studying how they actually work, they would work just fine. So I marked out the location, grabbed up a 3.25" hole saw and went to work on the lower windscreen.
They popped right in and function just fine. Do note though, they really do rely on a accurate 3.25" hole or they would be loose as a goose.
RIDE REPORT...
Ease of installation: 9.0 No brainer, just cut a 3.25", cutting from both sides. They do need to be "fit" to the windshield plastic though.
Comfort: 9.0 They really do allow and direct more air inside the cab. It's like the vent in your car, once you get up to speed and they feel great. They should be real nice to improve airflow.
Dust Prevention: 4.0 This was really my impetus for the entire project and it was not to my expectations. Although it did reduce the dust somewhat, with the split Honda windscreen open it was still dusty. You could at least get a breath of air putting your face in front of the vent. With the rear window down and the vents open though it DID appear to have a significant improvement in the dust.
Overall I can recommend installing these vents. They are VERY inexpensive, $14 for 2, they fit very flush and tight when closed and are easy to operate on the fly.
F325A – Snapvent Plastics