Despite its rather inelegant styling Ferrari’s 599 GTB can rightfully claim to be the company’s greatest GT car for decades.Launched back in 2006, the 599’s traditional front-engined V12 configuration immediately found favour with enthusiasts. Over its lifecycle it has the 599 has seen some outstanding spin-offs. These include the alphabet soup 599 GTB Fiorano Handling GT Evoluzione and its epic GTO sibling, based on the absolutely crazy 599XX development car. Now another 599 is in the works.Spied testing at Ferrari’s famous Fiorano test track this week was a disguised 599. Although it remains unclear if this test car will germinate into the final incarnation of Ferrari’s 599 or become its eventual replacement, the technical details are interesting none the less.Trackside sources reveal the V12 test car's shift regime is managed by Ferrari’s DCT transmission, instead of the series 599’s automated manual, and is quite possibly being used to evaluate the company’s forthcoming KERS road car energy-recovery system. With Ferrari boss Luca de Montezemolo having promised a hybrid 599 for future released back at the Geneva auto show back in March, this could quite possibly be it.