AFAIK the solar system is moving at essentially supersonic speeds through the solar medium, which causes the bowshock, so couldn't this just be an eddy current we've been unable to distinguish either because it's not present in smaller scales, or simply because it's normally small enough to be a statistical anomaly?
The physics of our solar systems action are essentially similar to small body physics, the problem is that they're blown up on scale unimaginable to us. Essentially our comparison of physics is akin to comparing getting up to turn the tv on with a trip to Alpha Centauri and back.
I still maintain you can't do do supersonic things in space. The would imply sound moves in space.