The function tuning that increase the performance of the car is available in "Initial D Factory" and also after the race.
Increase performance of your car with using "Driver's Point" that earn at race.

Start the tuning from the car of "NORMAL" and it becomes "EX SPEC" when tuning proceeds to the end of "SPEC 5".
Furthermore, the tuning becomes "EX FULL SPEC" when tuning proceeds to the end of "EX SPEC".

You can enter each Aero / Supply parts shops from "Garage" of "Initial D Factory".
Use "Drivers Point" which won at race to mounting and exchanges of aero parts, Wheels and mufflers.

* Please note that some of car models can not change the aero parts.