So im designing an enclosure for my btl thats coming in for my crew cab truck thats going to sit on top of the seat and im not sure what the best orientation for the sub and port are for trucks for the most spl. Is it sub forward port up? Sub up port up? Heres one design that i put together, about 7.75 cubes net after displacement, 32 hz, the port will be facing up and sub forward. Are there any design flaws that you guys can see with the port? Is there enough space between the end of the port and the back wall of the box? Any other recommendations or comments?

I'm not quite sure what you mean by "sit on the top of the seat".

Other than that, your design looks OK...

sit on top of the seat as in i have the box sitting on top of the back seat with the 42 inch length spanning across the width of the seat and the 24" vertically against the backrest. I just have to figure out a way to secure it so it doesnt fly off when i brake hard. This wont be my daily setup, i have two treo 10's in a box that fit under the back seat for daily.

i just went on RE website and used that build-tool and started designing one for that identical sub, did u make the second part of the L-port 0 so that it is just a single straight port?

got another ?, is the box volume that it states in the box calculator ur volume after displacement or before? so like in ur build is the 8.014 box volume ur volume after or before displacement? thanks

L2 port is 0, 8.014 is after the displacement of the port but before the displacement of the btl (0.26 ft3)

32Hz is awfully low for a competition-only box, I'd start experimenting and find out what the resonant frequency of the cabin is before building something...

its not for comp, i just want it to be a good all around daily that will pick up the low notes very well. What do you suggest i tune it to?