I have a 2005 S. The air cond didn't seem to be cooling down to as low a temp as I expected and took it to the dealer. They told me that the coolant was low (1 lb) and added some. After we left, I only noticed a slight improvement and was wondering if anyone has had similar problems. It was not a hot day (75 degrees). How cold is typical of the air coming out of the vents with the air on the coolest setting. Also, is there an internal regulation system to prevent itself from freezing?