adrock, this is an old rumor which came about right after the rumor that RS4 production had stopped. RS4 production never stopped, it was always slated to run through the 2008 model year. After this came the rumor that the RS4 engine power was going to be increased to 450 HP. I always thought that was a conflation of the rumors about a 450 HP TT V8 for the RS5, but who knows. However, you can order a 2008 RS4 today, and if you look at the Audi site you'll see that it has a 420 HP engine. Even if they did produce a newer version with a 450 HP engine, it would require a retune of the ECU and probably a new US EPA certification, something I doubt they will want to do in the US market as the end of production is approaching. But, given the 500 HP rating of the Champion Audi Vitesse RS4, with stock internals, a modified ECU and modified exhaust, there is still some unlocked potential with this engine.