The Ford Fiesta is a great little car. We got to sit in one at our state fair. I'm 5'9" and fairly long-legged. I sat in the front passenger seat, and put the seat where I could be comfortable (but not all the way back). I then went to the rear passenger seat and I had enough leg room to sit. It would not have been 5 hour road trip worthy back there, but manageable for around town.
I bet you could get an EFTA in it and the passenger could still be reasonably comfortable. But, that's just a guess. I don't know about the driver's side.
I can't recall about 3 across fit. It has a bigger interior than I expected, for a small car (and one that gets 40mpg hwy).