Yes, there are actually companies out there that will modify a Ferrari. While that may seem like sacrilege to many enthusiasts, apparently, for some, owning just a plain old Ferrari just isn't good enough.
Mansory's Stallone is based on the Ferrari 599 GTB Fiorano. The Stallone's engine additions include custom made air coolers and high-performance compressors. Altogether, Mansory engineers boosted the V12 engine's horsepower from 620 to 720 which contributes to the car's ability to get from 0 to over 60 miles an hour two tenths of a second faster than a 599. Mansory also boasts of the Stallone's upgraded interior materials and improved aerodynamics.
In a similar vein, Mansory also makes a heavily modified version of the Lamborghini Aventador producing 1,250 horsepower. For that car, Mansory weaves all its own custom carbon fiber body parts.
When a high performance luxury car isn't enough, buyers turn to tuner companies like Ruf, Hamman, and Gemballa to boost horsepower and change the car's appearance.