Messing with the window shape sounds hard.

Looks like an Insight mated with an xB and gave birth to a minivan.

Yeah, some of the mods would be more inclined towards making the air take the same path they take around the Bionic rather than faithfully replicating the shape... What I mean by that is that in certain areas, like probably the roof, I'd try and use a deflector to make stable vortices that round out the shape, rather than adding a bodywork humpback.

Another option for airflow control to try and force the air to flow round a profile different to the actual surface shape is similar to that artillery shell method, and I believe may be used on some classified munitions and projectiles. This would be high voltage charging to either push air away at certain points or to pull it back in.