Yeh i'm not getting full defrost (Not much airflow to the windshield) The thing is i can only hear that hiss while i'm coasting and blipping the throtle. Removing the radio and checking the lines didn't reveal much (no obvious breaks or damadge) and with it all apart an in full view,starting the motor revealed no obvious leaks. It's kinda hard to drive and check for the hissing at the same time. I'm wondering if the valvle that switches the flap could be leaking,but why am i only hearing it when blipping the gas while driving and not stationary?