734 horsepower Enzo?

On my way into work this morning, driving South on Canon in Beverly Hills I saw a red Enzo pulled up to the curb, with the driver speaking with a parking attendant. I quickly rolled down my passenger window to hear the engine note, and immediately noticed a decidedly louder and lower bark to the car at idle than the 2 other Enzo's I've heard. Unfortunately he didn't pull away from the curb until I was some 2 blocks away, but I could easily hear the car when he gingerly pulled away. The car had personalized Illinois tags reading "734 HP". Other than an obvious exhaust mod, anyone know what available (though unnecessary, if not sacreligious) engine mods there are for the Enzo that would boost it to 734?

As a side note, not 30 seconds later I saw a 612 Scaglietti heading West on Wilshire. Appeared to be either Titanium or Grigio Alloy. I guess deliveries have begun?

 

Thanks. Though I obviously need to clean my glasses off, I feel pretty confident that the exhaust must be aftermarket. Are Tubi, Capristo, etc., making exhaust systems for the Enzo? Having heard Armen's Enzo last Saturday, and a few others as well, this car seemed noticably loud and throaty at idol. Despite out of state plates, given the fact that it was at F o OC I assume this car sold/resold locally. Anyone know re: the exhaust?