Ha! Welcome aboard. I have the same car - a 2007 S with A/C and nothing else. Sticker says it had a block heater, but I guess it's MIA.
Mine buzzes too, but haven't gotten there yet. I did a thermostat - those suck. Reportedly, you can take out the passenger headlight housing to get easier access. I also did an alternator, which was not bad to replace.