the rattle is a scrifice that needs to be made, hacking up the OEM pillar does little to help intall and makes things way tougher to plumb and maintain.
The Auotmeter pod is the for this application is some of their best work. That does not mean it fits OEM but is very good compared to other models and years. A little down home effort and ingenuity can make the install premium.... a little clear silicone here and there and the plastic won't rattle. I know because I have put them in for the most sensitive customers and I got paid.
Think through it and some simple shop supplies can always imporve any project..... By the way, clear RTV is my favorite:evil