topless is right. the difference w/ the brake upgrades is not the stopping distance. it's how many times in rapid succession you can panic stop without boiling the fluid, fading the pads or causing a fire.......
with cars like the cayenne, even a single panic stop from 100mph could cause fade problems if it had the brakes of, oh, a boxster...... weight is a concern.
with a tiny car like the box & only street driving, you will, as i said, see a net performance LOSS due to the added unsprung weight if you put cayenne brakes on your car. now if you want them because they look cool, well that's a different issue.
