**DISCLAIMER** I am not a financial adviser, always do your own research. Invest only what you can afford to lose!**
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https://www.youtube.com/watch?v=mYGjzWu84-w
Added two port holes in the the back subwoofer panel. The stock stereo now sounds amazing! Make sure you either code out the fake engine sound via bimmercode or disable it by unplugging!
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https://www.youtube.com/watch?v=paH5Wqu7T0s