Let me ask you something. You do realize the 4.6is in the model year contained the largest and most powerful brakes on any BMW model offered for sale ?
Do you know how much performance benefit you will gain from spending thousands on brakes ? Do you even know the performance numbers - to justify the benefits ? VS upgrading to the best tires you can afford. And does the cost justify the modifications ? Im just curious.

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2003 4.6, esotril blue, over 215,000KM. Every previous owner failed to keep up the vehicle maintenance. Restoration project.