An interesting excerpt from this article:

"Audi Sport invests in modifying the existing factory to accommodate its cars, builds the appropriate special parts and manages the logistics of getting them to where they need to be at the right time in the assembly process. Audi Sport engines are also built in Audi's same mega engine factory in Hungary. Most roll off the same assembly lines as every other engine, although the R8's V10 and the RS3's inline-5 are produced by a single worker."

Does it indirectly confirm the RS3 engine is half R8 as has been talked about? So the RS3 engine is half Lamborghini Huracan :) Can't wait...