I live in ontario. have owned my 340 for 36 years. For winter preparation, put it in the garage, don't apply the e brake, put stabilizer in the fuel. leave the battery hooked up. do not put it on jack stands as the car was not designed to take that type of weight load. modern tires do not get flat spots. leave the windows open a crack re to save the rubber window seals. change the oil in the spring. this prep has kept my car very happy without issues for over 3 decades.