Need for Speed: Carbon Discussion
Then select "performance".
And you should be able to tune the performance parts + purchase better packages from there.
How CAN you do it - when you select the package you wanna purchase, a mini-menu will come up for the part. Here it will state the various aspects of the part that you can choose to customize. Let's take tires for example, at the top left it will state "drift"; on the right "grip". You can set the various aspects of tires that best suit your preference. If you want to drift more, you will set your preference to the left. If you want the car to grip the turns then set the preference to the right.
That's how you get custom settings.
How SHOULD you do it - select the preferences that best suit your racing style.
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