I had to pee during the entirety of The Lord of the Rings: The Two Towers and drank a giant icee during the movie without peeing my pants. I could probably hold it for half a day if I didn't drink anything while I had to pee.
When I really can't get to a toilet (like in rush hour traffic) I wiggle around in my seat sometimes making people think there's some boots knocking in my car when really I'm just trying to avoid ruining the upholstery on my seats. I call it the Pee Pee Dance because that's what my mom called it when I was a child. I would wiggle and dance around to make the pee go away. She would say "Stop doing the pee pee dance and go to the bathroom" Because she knew it would only work to a point. LOL