I have a 2004 tundra double cab with the JBL stereo and 8 speakers. By the way, the stereo is made by Panasonic. Anyway, the 2004 tundra did not come with a subwoofer. I see on posts for 2007 tundras, there is a subwoofer installed. Where did toyota put the subwoofer? I am installing an aftermaket low profile subwoofer and the cab is tight for placement. Can anyone help?