You need 1.000.000 credits for this.
First go to Brand Central -> Europe -> Germany -> Audi -> Showroom -> and buy the R18 TDI (Audi Sport Team Joest) ‘11.
Next return to main menu and select Scapes -> navigate to page 3 using R1 -> select Le Mans -> All Scenes -> select any scene and then choose your Audi R18 TDI and place it. Make any wanted settings and then switch to camera and take the shot.