Followed the Civic X video to address the A pillar rattle:
https://www.civicx.com/threads/passe...7/#post-606070 . To address the passenger side pillar, the solution in the video is less than a half-inch square piece of adhesive felt pad and precise in where to place it. Though I didn't think I had much rattle on the driver side, I went ahead and did it anyways. The instructions in the video suggest three similar sized pads there because you'll be mounting them on a larger piece of hardware. Only note I'd suggest after having done it...when resecuring the screw for the pillar cover, lightly hand tighten only...the screw is metal going into what I guess is a plastic bracket (allows breakway if the airbag goes off). Overtighten too much and it eventually won't be snug.
Once I removed my Insight's pillar covers, I noticed padding that wasn't shown in the Civic X video. The padding however is too high up to dampen the rattle that is closer to the dashboard.
Test drive today in the 40 degree cold...got me back a nice quiet Touring as opposed to my old 2007 Civic which had all sorts of creaks that I never addressed after buying it 3 years used. We'll see how it holds up through the weekend.
Video demonstrates how the pillar sounds if it isn't properly dampened - if you have a rattle here, this is a solution worth trying at home rather than having a Honda technician diagnose and address. Or you can at least request that Honda tech dampen the lower part of it.