Getting into the McLaren F1 was easier than most other race cars I've tried, despite the center seat. The rollbars work perfectly to help yourself in.
The cockpit was comfortable, even for someone my size. It was definitely set up for someone taller though, tons of leg room.
I honestly could not figure out how to open the door from the inside.
Getting out was a little tougher then getting in, I tend to use the squirm-then-fall method.