That is one helluva car. Got to see one first hand on a track in Joliet IL (Autobahn Country Club) being driven by Audi employees at an Audi one day class I took in 2007. Incredibly cool. But make sure you get the V10, not the 4.2L V8 in today's model. If you're going big, why not go all the way?
And every AMG Merc that could 'waste' an R8 has an automatic trans. If I wanted flappy paddles, I'd buy a Ferrari.
That car is awesome (if you're a 17 year old Japanese kid with a worn out "The Fast and the Furious" DVD in your house).