Subwoofer help 15's in a mustang?
1. You can't even drive yet?
2. If you don't know, check for yourself. I'd say you'd need at least 18" of space to fit the height of the box with your subs in it, and consider the depth of it as well. Your seats don't fold down even with the bottom of your trunk, so it goes in on a bit of a diagonal. I doubt you'll fit 15"s in there. Get a single 10 or 12 from a good quality name. The mustang has a small cab, so you don't need 2 15"s. A single quality 10 or 12 will be plenty.