Chris is right. What is so deceptive about how big of a person these cars can swallow is due to how the legroom is positioned. The footwells actually go past the engine, so when you are in the car with your feet on the firewall, your feet are almost in line with the #3 cylinder, and your shins are roughly at the flywheel.
I am relatively short (5'6"), so I don't have any problems with the legroom. Getting out of the car is a different matter altogether, though, as even someone my height has to be careful about not tearing up the door cutout trim with my shoes. Once you get used to how to manipulate yourself out of the car though, it's easy.
I'd love to have an MGBGT, or even an A, but they are hard to find around here. They're easy to work on as long as you don't mind getting a hunch in your back from stooping over.