It boils down to options, your sports car, track car, M car or AMG car, its comes down to options.
AMG gives you sports options, and there are alot that the Merc dealer does not sell but you can buy them from AMG Germany direct as I have done it the past.
If you look at brake options, you have them for Mercs, Porsche, Ferrari, etc.
Whether you track your car or not, or the manufacturer say we don't need better brakes, most of the others give you an option. BMW don't give you any (they do now on the 1series). If they were worried they would not fit under 18" that's fine, so you buy a brake upgrade plus 19".
AMG standard wheels are 18" with 6 pot fronts & 4 pot rears. I don't mind if I have to pay for them but as least give us a reasonable option. We get options like manual to DTC, coupe, vert, sedan, paint, wheels, interior options, audio, CF roof, sunroof the list goes on but no brake upgrade. BMW could probably pull another $500.00 profit out every car they sold if they had that option.
I thought dealers loved selling you the option becasue they could make a large profit out of accessories?.
Here's a new poll to start:-
Would you buy a BMW Caliper upgrade for your M3 for $2000 ( what would a caliper upgarde cost at production time, $250 per wheel BMW cost)
Red, Yellow, Silver or Black
X5 F15 M50d White, 20"rims, Yellow Calipers, Ceramic Pads. Better off saying what it does not have and that's a B&O Audio System, otherwise all option boxes are ticked.