Are you sure its just the radio?
Ive been laid up in be for a while and i havnt driven my car for a while and when i first got out of the hospital mine was going dead after a couple of weeks and i have an aftermarket "kenwood" unit.
I thought it was the alarm, when i lock my doors i have a little light on the dash that blinks constantly
Ide like to try it, but what fuse goes to the radio? if i could pull that rathe rthen unhook the battery every day ide rather do that.