Depends if you value booming bass over trunk space.
Personally, I value trunk space. You can put 8-10 inch subs in either the rear deck or rear quarters. You would build a couple of boxes for the rear quarters, but there is no room to build an enclosure in the rear deck. For the deck, you would simply get free-air or infinite baffle compatible woofers.
I put two 8" subs in the rear deck.
You can easily run wires to the trunk by removing the lower door sill cover, and the rear seat.
1 of 97 - Quicksilver Metallic, black leather, factory 18"s, CAGS eliminator