alright so I will start building a sub box pretty soon but I have an issue, there is a metal brace on the floor of my car going from one side to the other. can I work around it? or does the box have to be flat one all sides?

You can make it any shape you want, no need for it to be "flat" all around. 

aslong as the airspace is right ?

Correct. And port area if going vented

correct...alot of guys with pick me up trucks have all different shapes going on so that the box fits behind the seats and around the drive shaft

drive shaft? dang were are they putting their boxes

If you have the space you can always do a false floor.

my space is very limited unfortunately

Stupid laptop.. sorry.. ignore this. haha...

Edited April 19, 201312 yr by SacredTanakh

lol dang bro haha

lol dang bro haha

I know, I just need to stay out of your threads haha... carry on!