Small trunk have 2 10 subs better box idea

I drive a 99 Nissan Sentra and I have two 10-in subs in the trunk in a box already the box is too big and bulky. I have no room in my trunk for anything! what are some links to some better box designs that would give me the most room in my trunk but still have my subs sounding good?! Looking to DIY . And obviously something that's not going to cost me an arm and a leg?