dan, flutes would NOT look right on the standard bodied gtr. you need something to hide the muffler abit like johns car has the opening in the rear bar or like a vertex rear bar does.
imo, i think if your going to leave the cars body standard, you should go a decent chuncky cannon style on the angle. get the tip of the exhaust hanging out the back of the car abit but keep the muffle tucked up in the car if you can.
btw, the first pic is straight pipes not flutes which is what ill be getting soonish