I found this link in another thread, but it's well worth a thread of its own.
Hoppen RS6
"The full-house package includes sport turbos, different head gaskets, a new fuel pressure regulator, new spark plugs, high-pressure silicon hoses, a high-volume fuel pump, freer-flowing twin air filters and—the heart of the package—software tuning to the electronic control module for the engine and automatic transmission. There is also a full stainless-steel exhaust system, MTM 19-inch Bimoto wheels, Michelin Pilot Sport 275/30ZR tires, and an MTM upgrade to the Brembo front brakes.
As for the suspension? “Already wonderful. Nothing much we can improve upon there,” Hoppen says."
"Most anyone can reprogram an ECU to make more power, he says, “but they know exactly how far to go: how much the engine will take, and how much torque the transmission will take.” "
Their homepage is not the best around, but here it is anyway:
http://www.hoppenmotorsport.com