Not an S6 but Love it.

From the article:
The new power package promise to bring a stronger shock to the less glamorous versions of the A6 range, starting with the Audi A6 2.0TDI which normally makes 190PS (187hp) and 400Nm (295lb ft) of torque. ABT offers a separate control unit which increases the power and torque figures up to 215PS (212hp) and 440Nm (324lb

Photos and article - 404HP Audi A6 Avant by ABT