Well, first off, not only will you have to have the door molding shaved, but also the molding as it runs onto the front fenders and rear quarterpanels. This can get a little expensive, so I'm wondering, why do this anyways. Save the money from shaving them, and either have them painted the same color as the car if it bothers you so much, or spend money on other performance parts. Prioritize what about your car you think can be improved as far as the driving experience goes. Does it need beefier brakes, more go fast parts, handling feel sluggish, etc.?