I understand Rick's logic:
1. The C6 will likely have similar shaped headlights as these are also similar to Ferrari's (overhang, of course, is far too long on Callaway).
2. Power-bulge in hood is not divided as in C4 & C5- a single "bubble" but not as wide at the top here, as seen in the black NM car. A similar C6 termination at front of power-bulge is possible as it suggests C2.
3. Large single opening "grill" is probable, jujube, et al.
4. Fenders shapes result in a Coke bottle shape as suggested (but softer in pilot) in the high altitude testing white cars.