Sounds like you need lubrication

There's several ways to make this happen, you just have to want it bad enough. I know that's definitely not a viable solution for everyone. I'm well over 6 foot and I can sit comfortably in mine without touching the roof or being above the roll bar.

Also, older is easier. The newer they get, the less space they have. I couldn't even begin to fit in a new one until the seat rails were replaced with aftermarket.

My dad used to own a Miata, he was unable to get on and out of it with the top up. I loved borrowing it when I would visit because I'm a foot shorter than him and never had any problems with it. There's some perks to being short.