After some extensive research, I've got the lineage of this car's development over its 4 seasons mapped out (2007-2010, inclusive). While there were many small changes across the car, the most visible external evolution over that time was focussed on the rear panels and the shaping of the rear fenders. This means the forward bodywork and chassis can carry through all versions... Le Mans low-drag nose being a notable exception.
The 2009/2010 version with the ACO's narrow-wing regulations is modeled here.
The model's bodywork is 80%-ish done here. The proportions and dimensions fit the regulations and match all the source images with a high degree of confidence. Under the skin is also a monocoque chassis and I've just started blocking in the drivetrain. It's gonna be nice.
(This render is my Metasequoia file converted to 3DS and rendered in Rhino's Mac beta. I'm just starting to fumble around with Rhino's lights and shaders... good stuff)