The CX-9 is not a longer version of the five-seat CX-7. The mechanical underpinnings are different and the structures of the two vehicles are not related. The CX-9 shares some components with the five-passenger Ford Edge, although the Mazda is longer, by 2 inches of wheelbase and 14 inches overall. In fact, the CX-9 is the largest Mazda ever. Its overall length of almost 200 inches makes it nearly a foot longer than the 2008 Toyota Highlander or the 2009 Nissan Murano. What is perhaps most surprising about the CX-9 is that it doesn't look big from the outside.

The CX-9's nose features a huge Mazda insignia and prominent, flared fenders that lead a character line heading back and slightly upward just below the windows. The roof arches, crests and then slides back and down. One surprise is a pronounced bulge in the tailgate, like an old-fashioned bustle. It is a neat trick that adds a little extra storage capacity.

Safety researchers say the strength of the vehicle's body is also crucial in providing protection in a side-impact crash. Mazda took this into consideration, providing B-pillars that are extra wide and strong. (The B-pillar is the second roof pillar back from the windshield, which uses the A-pillar.)