kinda dissapointing...not that ill ever own one...
http://www.autoblog.com/2008/03/20/did-we-say-50-50-audi-r8-v12-tdi-not-coming-4-2-v8-tdi-instea/
When we heard that there was a 50/50 chance Audi would be offering a production version of its R8 V12 TDI LeMans concept, our interest was piqued. The thought of 737 pound-feet of torque rippling the pavement behind the mid-engined R8 supercar will, unfortunately, remain but a fleeting fantasy in our power-hungry dreams. According to Michael Dick, Audi's head of production, the V12 TDI is not slated for production. That's the bad news... the good news, though, is that there is a coming diesel engine option in the form of Audi's 90 degree 4.2-liter TDI V8. In the Q7 SUV, that engine produces 326 horsepower with torque registering in at 550 pound-feet. While it's no V12, we'll happily take whatever oil burner Audi wants to throw our way.
http://www.autoblog.com/2008/03/20/did-we-say-50-50-audi-r8-v12-tdi-not-coming-4-2-v8-tdi-instea/