in my camaro i have just a universal turbobass probox, but i have the port facing up...i did notice by having the port closest to me vs closer to the tail i didnt notice any difference in sound(other than less vibrating of hatch) tho when i angled the box so port was angling in towards cabin it seemed a little louder....also something to think about, when i first got the system i had box sideways(sub facing up port firing into the 4 or 5"s between box and cargo space wall) and it didnt necessarily seem quieter just different, but a whole heck of a lot less vibrating from the hatch...idk if thats just a problem on my hatch or what...but if you have port facing up close to hatch lid...be prepared for a hecka lot of vibration noise from the hatchlid...just my two cents