The only performance parts that truely do anything are those that are bolted on the outside? HAHAHAHAHAHAHAH. You got one thing right though. The true performance parts are those that you can see. When that Z car lining up at the start line beside you takes off and you seeZ that cars rear and you seeZ and eats his dust. Performance first and then coZmetics. What's the point of having a Z car that looks like a million buckZ but cannot even start. A true racer worrieZ about cosmetics last unless the damage to the exterior/body is so bad that it's killing your performance. So remember, you might not see the pistons, cams, valve, and the porting and polishing, but you iZ gonna see the rear of the other Z when you iZ getting burned