spazmoid

Hey guys, I got some gremlins running around the car, 89 300sel. I've got static coming out of the left speakers with the car off, on, and radio off or on. It's draining the battery because the car just sits there, off, with the speakers crackling. Yesterday when driving the sound in all speakers would silence when the headlights were on or i touched the brakes. And then 2 minutes later it was fine. I've cleaned the battery terminals and checked the connections behind the stereo and that hasn't helped. Any other ideas?! Thanks