Rob, the most recent animated video of the SketchUp model shows the interior fairly well:
The driver sits in the center, and along with the two flanking passenger's seats, three people my height (6'-4") or taller should be comfortable with lots of leg room. The fourth seat is for someone about 5'-8" or so, and the fifth person can be up to about 5'-0" tall. The seats are staggered (because of the tapered sides) and there is an narrow aisle on the right side; kinda' like a small airplane. You have to stoop lower as you move forward. The only seat on the right side is a bit farther back from the driver, making enough room for the driver to pivot around to sit in the seat.
Here's some images - the first shows just the seats:
Then after I added the 3D human figure, I tweaked the front passenger's seats angling them slightly outward so the heads had more room under the roof:
