That looks like a great solution!
What is that mount you are using?
Did you get the mic off EBay or did you get it from a local store?
The sound in your clip is great - I'm totally convinced.
I find the mic on the GoPro to be basically useless so I'd love to get something worked out like you have.
BMW - 135i DCT
Audi - Q5 3.0TDI