Participate in the indicated number of races for a specific vehicle class to 
unlock the corresponding item that can be customized for that particular class 
(Tuners, Muscles, Luxury, Exotics, or Superbikes):

Blowers: 45 races 
Car headlights: 36 races 
Car spoilers: 18 races 
Car stereos: 27 races 
Exhausts: 45 races 
Front bumpers: 9 races 
Front seats: 27 races 
Hoods: 36 races 
Intercoolers: 45 races 
Motorcycle bowls: 36 races 
Motorcycle tails: 18 races 
Motorcycle tanks: 27 races 
Post gauges: 27 races 
Rear bumpers: 18 races 
Skirts: 9 races 
Steering wheels: 27 races 
Taillights: 36 races 
Widebody kits: 45 races