I'm trying to do the same thing currently. I have a 2004 Cayenne S (Lapis Blue on Gray). Here's what I have done so far:
1. Replaced the 18" wheels with 20" Cayenne Sport Design wheels for a sportier look. Yes, 21" would have been more authentic, but I got a hell of a deal on a used set of 20's.
2. Had the brake calipers painted red by a local mod shop, provided them with "Porsche" decal templates from Rennline for the white lettering (tip: get the largest ones they offer for both front and back, they turn out great).
3. Tinted the front windows to match how the rear ones came from th