After getting a new GoPro, I found the sound was basically useless. You either have it on the trunk where the little internal mic is overwhelmed with drone and bass...or you have it up and out of the way but in the windpath. To keep the camera out of the wind, you had to put it somewhere with virtually no view (i.e. bumper looking backwards etc).

So, I bought this external microphone to see how it would work out. It's pretty much perfect for this stuff. It was $20, is small, has a 20 foot long cord that is thin enough you can close the cord in the car door and all is well.

-Audio Technica ATR3350. About a $25 investment at most. Comes with a 20 foot long cord which is perfect for mounting the GoPro where you want, and the microphone anywhere else on the car.
-GoPro Hero3 Black
-GoPro 3 3.5 mm external microphone adapter


Hopefully this helps those who are looking for JHM exhaust sound or who just like listening to cars (I do this on youtube a lot lol). This is JHM downpipes (catted) + catback (resonated). Otherwise stock.










Then a couple where the microphone is actually in the engine bay, taped to the intake/MAF hose. Lots of mechanical whirring going on in there. Sounds great when it's WOT. Cool to actually hear the engine. The interior of the car is normally so quiet that you rarely get to hear engine sound. THe E9X M3 has a lot more in cabin sound and sounds virtually identical at WOT.