Here you go for sharing in case anyone is interested.
Brake light flasher is not only cool looking but it alerts driver behind you whenever you step on the brakes.
Very simple mod, takes 5 minutes to do.
1) Remove panel. Panels are held by plastic clips. See photo below.
2) There's only two wires. Brown wire is negative / brown (this is common for BMW wiring.) Positive is Yellow wire with black stripe.
3) Follow the instructions provided in the 3rd LED brake light flasher on how to hook up the wires.
4) I dont recommend using the provided crimp clips. Those are terrible. I've used them before and instead of crimping the wires most of the time it actually severs the wires and will not provide a good electrical connection. I recommend using a good butt splice.
Photos below.
Here is the 3rd LED brake light flasher that I used. There are so many different types of flash modes. I recommend not messing with it and just use the default mode (Flash 6 times, then LED light stays on steady.
http://smile.amazon.com/gp/product/B...?ie=UTF8&psc=1
I was not able to take a video on my M4 but here it is when I used the same flasher on my 2003 Ferrari 360 Spider. You can fast forward to time 2:25 to see the effect. The light flashes 6 or 7 times then goes steady lit.
Hope that helps some of you.
Dan