Cookie 11,
This is one of the big reasons I am waiting on the Maverick vs going out and buying something else. If you watch some of the review videos of actual bodies in trucks you can see larger men sitting in the back with enough legroom to be comfortable at least. I have little concern about getting my thirteen-year-old and car-seated three-year-old in there.
Jump to the 10:00 minute mark and you will see adults sitting in the back, 8:00 to 10:00 is discussion on the features of the back seats.