Grand Prix Story

There are two S class vehicles in the game: the Kairo Car and the Mach Car.

The Kairo Car you get from winning the 'Kairo Grand Prix'. Not that easy to do. I was able to do it with a full gold Super Car (100% with gold auras only) + full gold V12 (100% with gold auras only), a supercharger (100%), hyper oil (100%), and slick tyres (100%). My final car stats were about 780 speed, 583 accel, 451 handling, 405 dura. Driver stats were about 120 pedal/100 shift/137 steer.

The Mach Car you get from upgrading both Spiral Car and Aero Car to at least 50%
→ The Spiral Car is an upgrade from Cigar Car at 50%, which is an upgrade from Dragster at 50%.
→ The Aero Car is an upgrade from Sonic Car at 50%, which is an upgrade from Wing Car at 50%.