Just got back from biking with a friend and noticed an aero detail (I believe) of the tail light of his Nissan Murano (like this):
Note the 90 degree step in the edge of the plastic, which I assume is there to promote clean separation (in the same way
Daimler uses vents on its rear tail lights for the same purpose and GM added a
pronounced "step" at the trailing edge of the Volt's bodywork:
Of course Nissan only applied a small aero band aid on the Murano. For styling reasons (I guess), the large presumably aero-unfriendly radius in the greenhouse transition from the side to the rear in the hatch area is left un-creased.
The Firefly/Metro has quite a lot of curvature at its side-to-rear transition from the hatch, through the tail lights down to the bumper cover. Zero attempt to fix a clean separation point. Hopefully addressing this soon with the boat tail...