2013 GS Coupe 6 speed. 4000 miles. Occasionally the HVAC just blows ice cold air no matter the temp setting. It may come out of the floor, dash or defrost vents. Controls are not effective other than the on/off feature. Sometimes can shut off car and restart and all is fine. Sometimes it just starts working again. Never had any work done to it. Not even an oil change yet. (It leads a very sheltered life) Dealer says they can't reproduce the problem but they think it is an actuator. They don't want to replace anything because it requires "taking the dash out". They say to wait until it does it again. ANYONE ELSE have this problem?