Try adjusting the seat again on both the 3 and 5. I am six foot and didn't need to squish myself forward as you described to get back seat legroom in either car. The 5 is wider laterally, both from and back, and thus more comfortable (IMHO) for adults, but it does not offer much greater legroom. That being said, if you are looking for good rear seat room for full grown adults who will sit in teh back for along period of time, you are looking at the wrong cars.