If you are using an auto battery, you'll notice there are holes in it. If you look at your cart, you will notice notches.
Put the cart on the battery as tight as it will go, then loosen it slightly. It will take a small amount of time, but just make sure you can see one of the holes in one of the notches. That'll get rid of the WHISTLE.
After that, you should notice a slow, easy drag. Practice makes perfect.
As for vapor, if you inhale and hold, like a regular cigarette, the less vapor you will produce upon exhale. The longer you hold, the less vapor comes out.
Hope that helps. Let me know if I can help any further.