found a few interesting shots on the interwebz....
a few spie shots from the car apparently on top of a truck, wich reveils some bits of the front and rear undertray.... nothing terribly shocking appart from evidence that it's definately there...
rear diffuser
and a bit of the front
i've slightly lightened some pics to reveal more detail
edit:
notice the "ridge" on the taped over taillights.... small spoilers to deflect the air somewhere? makes sence, if you wand taillights that curve around the car to produce that optically wider tail, but you want a clean edge to sepparate the flow
also my dad mentioned last week (as he returened from a course about the new insignia he has to work on as a mechanic) special attention had been given to the shape of various components from the suspention (i assume the ones that arent covered by panels) so these wouldn't disrupt the airflow
the flat spot on the rear suspention arm visible on the merc might be another one of these hard to notice details that help it get low drag