Ford Focus RS with KMS Motorsport Firestorm recorded via Tow Bar Cam with an external microphone.
Video was taken using a Sony AS-10 Action Camera in modified waterproof housing, mounted to OEM tow hook bracket using a GoPro style handlebar mount and threaded adapter. A 3.5mm Aux cable ran through the car to an external microphone mounted to the rear of the car with a suction cup, thus maximising the exhaust note and minimising wind noise.
Camera was set to 120 degree field of view for this video, a longer video set at 170 degrees FOV will follow shortly (I personally think 170 degrees is the better of the two, let me know in the comments if you agree).
Exhaust is a KMS Motorsport 3" Downpipe and 200 cell Sports cat, resonated centre section and ending with KMS Firestorm catback with 4.5" Semi-slash cut Titanium tips.
The video does make the exhaust seem louder, due to the location of the microphone, however, the specific sound itself is accurate.