Everyone else looks lovely and normal. Much nicer than Her Travesty.I’ve made you a collage of the smarter dressed people. You can wear a hat, stilettos are a no no (I can’t work out if Carrie is in stilettos?) .
There are also lots of photos with people in jeans. If it’s a hospitality ticket then you can’t wear jeans .
---
I personally think a nice day dress somewhere around knee length or a tad longer is nice for this (if it was me) . I’m not sure I’d feel like wearing a hat to a car thing personally. Races yes and lots of other occasions I like a hat .