Completely different, or streched four inches? The Honda Odyssey and Accord ride on the "same" platform, despite the very obvious difference in size. And then there was the case of Chrysler's cars in 1990... why not build one good platform, then build a complete line of cars and minivans on it?
Now you've got me curious... where is this packaged, and what goes in the trough in the battery? Rear legroom?
Having no exhaust tunnel will free up space in the back. I hope they find a way to make good use of it.