How do I go about installing a 12 inch sub in between my 6x9s? Is it hard and what materials will I need?

Well... there are a few differant ways.. U can actually mount the sub in the trunk under neath the trunk lid and make a blow threw... U can mold a enclosure into the rear deck lid.. Some subs u can use in Free Air Applications. It wont be deafening, but itll add a healthy dose of bass to a lacking system...
Why do u want to do this?

haha i didnt understand any of those options. i feel like an idiot, but i dot know what trunk lid, a blow threw, or a rear deck lid is lol. can you help a slow brotha out?