I posted earlier about a creaking noise when changing air distribution modes. I made an appt. at the dealership before the warranty is up in 380 miles. I have also noticed a hissing noise coming from the passenger side under the dash when I have the heat on. Typically hear it more when I have the fan set on 1. Anyone have an idea of what the noise could be? Heater core, vacuum leak??? Heat and air seem to work just fine. Thanks...