Electrical Problems

I have a 2000 Mercedes Benz Clk320 Convertible. It ran great until 1 day the battery was dead. Replaced batter, alternator but still acting weird. After 1 day of sitting and not being driven the batter dies. Automatic trunk release doesn't work. The radio doesn't work, you can turn the radio on but no sound comes out. At first seats couldn't be adjusted then they would adjust in the opposite direction and now work fine? Had a couple shops look at it but they got nothing...The radio would ask for code and we would input the correct code and it seems like its tuned in on local radio stations but no sound..?? Any help???