I've waited so long for such a thing and searched it everywhere already but never found something useful and suddenly someone submitted THIS very interesting thing today: A complete pack of Sonic Rainboom stuff!
- Rainbow Trail
- Sonic Rainboom Particle Effect
- Speed-Trails (down left + right of the picture above)
- Simple MLP tree models
The video on the original website shows you how all those things will look like in your final animation!