PGDsx: That spike part your talking about is actually there on the Ztune bodykit for the skyline. Its a hole on the other side and serves as more airflow for the engine bay. The render angle doesnt show this off very well though. And totally agree about the ride height she's sittin a little low
Only flaw I can see is the top right of the front wing, seems to spike out a little. And the clearence between the front tyre and wing, I know it would look ace so close, but in reality you'd pull the wing out on the first bend!