I'm not sure if I'm going to word this correctly, so here goes.
On one of the threads you had mentioned that the box was approximately 2 to 3 inches from the rear door. Since the port is at the rear door and it is that close, doesn't that small opening between the box and the door physically become part of the port? Ultimately lengthening the port?
I'm a nooB when it comes to ports, but it makes sense to me that since the port has a specific length and surface area, that it has a certain resistance to the flow of the air/sound waves.
Let me know if I'm way off base, or if my thinking is correct.
It can lower the tuning a bit, and can help or hurt sq and spl. It really just depends. If the distance from the port to the wall is much smaller than the port width most would recommend against it. There are plenty of other people who could most likely answer the question better than me though. I've never had any problems though...
Troy has recent real world experience with this one and it seems to be working well for him. I have used a similar principal in designing OEM home theater subs as well... Finding the proper distance to terminate the port (in these cases flared ports) from a wall will have it act like the port is longer than it is. This tunes things lower without actually having to stuff a longer port in the same space. It takes a little work to dial it in... but definitely works.
Scott, the box for my q's is 8CuFt after all disp. Its tuned to 32Hz and the port is about 4" away from my hatch in my range rover. I couldnt tell you how long the port is but it is but it is 5"W and 23.5"H. How does this affect my tuning? If any?