Subwoofer Box Position In Sedan

[stevh0]

i have one dd 1015 in a 3cu box fairly high tuned around 48hz

i find the if i push the box right up to the trunk i get more low end shake out of it .

facing the woofer to the roof of the trunk the bass is cleaner but not as hard .

and facing it into the cab , the woofer sounds crappy and bottoms out .

if the box is not walled off to the trunk are there any cancellation issues making it sound so crap?