About the RPI Scoops for BMW E46 M3
The BMW E46 M3 RPi's Ram Air Induction converts your factory intake system into a ram air type. Other aftermarket induction kits mostly suck in hot air causing a loss of performance. The use of heatshields are not very effective as heat shields mainly work to block radiant heat. Utilizing the stock intake boxes, expect a 5-11whp gain with 70mph airflow. RPi's Ram Air come with a 30-day money back guarantee.