Audis are heavy as hell,the S4 is very near the weight of the S550, around 3638 lbs Kerb (basically empty) 329 hp 325 torque so I wouldn't expect it to get away from an ecoboost let alone a GT for $50kAudi would not gain many Mustang owners from this.....mainly from the price, Mustang €42K Audi at least €70K! I alread have an A6 Avant is and is very pleased with that and no way I would back down from the Mustang GT!
The Mustang and an Audi is in a completely different ball game....