I would doubt it.. Is your stereo stock? Unless you are running a crazy system or somethin. A stereo can draw current, but thats what a capacitor is for, I wouldn't see it taking all of the juice from your battery. Unless the battery is going bad.

98 Black Mystique; Duratec/ATX
"Mystique, the luxury SVT"

P.S. This is what part of the alphabet would look like if the letters Q and R were omitted...