In addition to being in a locked car I think the gun must be out of plain sight.
https://law.justia.com/codes/indiana/2017/title-35/article-47/chapter-9/section-35-47-9-2/
Driving by yesterday a sign caught my eye. School coming soon. Based on the article it looks like the children’s museum may have sold the property, so it would not affect the museum...
I was there yesterday. It was nice. Not much for crowds. Pretty sure there were at least a couple guests carrying. Security only needs to see your ticket and an ID is needed if it’s an annual pass.