Though you would probably know if you had a sub, you can easily fid out. the sub is loactedo n the back right panel, at the bottom corner, right next to the hatch door. If you have a sub you will see a defienate peice of trim that is separte fromt he others, but is the same color and still flush. You will see a small circle or square of mesh, like speaker grills, in the middle of this peice. If you do not have the sub, there will be a small indentationm or pocket covered by a net to be used as a small cargo holder in the same spot.