Numerous new R18 photos from Yas Marina test up on the Audi Sport International FB page (I don't know of where else they're at, but considering that Mulsanne' Corner FB page has a link to them, you can bet that Mike will be analyzing them soon), which raises the question: How do they expect to get the rear deck off the car, since it seems that the outer rear wing endplate is hardwired into the rear bodywork, and I can't really see any parting lines separating body panels. Also of note is that the outer endplate has significantly smaller surface area than the main endplate.
There's also a video of the R18 there, too:
http://www.facebook.com/AudiSportInternational
It also seems that Audi tested a 2012 LM spec R18 at Yas Marina along with a 2013 sprint race spec R18.