I would recommend putting a large fuse by the battery (for future sub amps), then branching off in the trunk with the appropriate smaller gauge wire with the appropriate smaller fuse. This way, you're not limiting future installs, might cost you $5-10 extra, and you're doing it safe. Even if you never plan on adding a sub for you, it's always a card to keep in your pocket to get extra value out of your car when you go to sell later!