I would go with a sealed because ur trunk is small and sealed would be the smaller box. I recommend 2.0-2.75 cubic ft sealed. for vented would be 3.25-3.50 after woofer displacement. Also I would recommend a reverse wedge meaning the woofer would go on the back side of the box not the angel side because u can slide the box in further saving u a little more room. I'm doing that same box now for the same sub but in a Nissan 2001 sentra. My box when done will be 2.78 cu.ft. After displacement. Sealed. 720 watt rms power acoustick 2ohm stable mono block to get longer life out of my sub.