If your box will be rather close to your hatch, I would do sub up port up. If your box will have at least 6 inches or so (depending on your port area) of space between it and your hatch, I would do sub up port back. Generally in SUVs sub up port back is considered standard, but I would not want the hatch to mess with the port tuning by being too close. However, some people would disagree with me and say that the closer the port to the hatch the better because it will have more "loading". To me, that just means that your hatch will rattle like crazy because it is blocking the port, giving the illusion of being louder. Just my two cents.