I have the door speakers and the tweeters on top of the door panels. But there is a small subwoofer in the rear shelf that is fired upside down. Looks like an 8" or maybe 10". Only 1 is visible on driver side of shelf. How do I tell if I have Bose or not, there are no logos anywhere that I can visually see. I tried to take the rear shelf out so maybe I could get a better look at it but I don't want to break anything. Any help??