I've owned my Mazda for a little over 2 months now, and I knew it had a lot of wires added under the dash, but I hadn't actually looked to see where they went. Well today I decided to clean it up a bit and I found an old alarm in there, apparently installed by chimpanzees.
I pulled the speakers too, since I plan to replace them anyway when I buy a head unit here soon. I've been riding without tunes and it's getting old. The speakers had these things on them though...
My best guess is that they're filters, possibly related to noise caused by the ghetto alarm install. Oh well, all that stuff's gone now, just thought I'd share.