Just like the Original Mustang Boss 302 that was developed after hours and got its name because whenever anyone asked what was going on, the team developing it said "oh, we're working on the boss's car," this new set of mechanical and aerodynamic improvements for the Pony Car that, according to Ford, bring the "standard GT" a further step closer to the phenomenal track-focused grace of the GT350, are the result of similar dedication that went beyond nine to five.

"A passion to create something special is what really drove this project," said Tom Barnes, Mustang vehicle engineering manager. "And that really showed in the off-the-clock way we went about doing our work."

Barnes and his team spent evenings working in the garage and weekends at the track testing the components, which include 19-inch wheels weighted and balanced to improve steering and responsiveness in the bends, a new front splitter and rear spoiler that are both for go rather than show, and an overhaul of the steering and braking.

The result, according to Jamie Cullen, Ford supervisor for vehicle aerodynamics development, is a car that "will just beg you to go faster. [It] has lightning-quick response and never gives up grip."

What's more, all of these enhancements will come on top of the enhancements available in the level 1 Performance Pack. They include a tuned chassis and anti-lock braking system, Brembo brakes, a bigger radiator, and a Torsen rear differential.

And now that the enhancements are a reality and will be ready to order as options in early 2018, the secrecy continues. The only clues that a Mustang is fitted with the Performance Pack Level 2 will be black detailing on the front splitter and spoiler and a 10-spoke design for the 19-inch wheels, which come wrapped in Michelin Pilot Sport Cup 2 tires.