This smell issue may be just the mold that normally builds up when shutting down the AC and the ignition at the same time. I've gotten into the habit of switching to "EC" a block or two from home to let any ice melt off the evaporator before shutting off the engine. Someone told me that you don't get a pressure surge that way too; not sure about this, but at $46 a lb, I want to keep all my freon