First off, the stock SRT-6 setup does provide substantial performance over the N/A and it is a great car to drive as is. However, you cannot deny the physics of hot air going into an engine. It is less dense providing less air in the combustion chamber.

Secondly, the stock intake is like sucking in liquid through one of those straws that you use to mix creamer with your coffee. The Needswings setup dramatically improves the airflow. The proof is in the pudding when you are at the drag strip or on the dyno. Compare the dynos or drag strip times of those who have a stock intake vs. a single or dual NW CAI setup.

The air filters that Rob provides with the single and dual NW CAIs would not hamper the cooling of the radiator in my opinion. If you are worried about heat, don't step on the gas.

Manufacturers like to play it super safe. We have too many lawyers that are willing to make a quick buck over the slightest thing.