Quick question- I just got an '03 Expolorer with 3rd row seat and the sub in the back and NO DVD player. I'm looking for an upgrade to the sub that might be a little more efficient or sound a little better. I'm sure the best thing to do would be an amp+sub upgrade. Has anyone else upgraded the sub in the factory location? If so, what's the wattage of the OEM amp going to it? I really want to maintain the stock look, but have a better sounding system. Thanks!