I recently bought my gf a new head unit to go in her tribute, and I was wondering if anyone else has done this and if they replaced the sub in the back. She likes havin the trunk space and doesn't want a box for that reason, and cuz she wants a little extra bass, nothing big and boomy like I have lol. Any recommendations on what to put in there? I was lookin at a JL 6.5, but didn't think that would be very good in a free air install