if you take the air filter out you will see an opening leading to another box that has a vacuum actuated valve. look through the grille openings under the lhs headlight and you will see it is open, that is where the bi modal grabs the extra air from. the rhs is actually blocked.
Interesting as the GTS doesn't have that grill opening, but it does seem to have one above its lhs fog light.
So surely some people have actual pictures of the bimodal system by now.