Just picked up a new Tacoma. Really like the truck so far. However I am hearing a strange noise when shutting off the motor. It sounds like a purge or release of vaccuum pressure.....almost a whistle sound. I really don't like fooling with the local dealer any more than necessary and was wondering if anyone else has noticed this with their truck. Truck seems to perform just fine and there are no lights on to indicate a problem. For what it's worth I have a V6 PreRunner with the towing package.