I was browsing and saw this thread... I really like this exhaust looks really good. I went ahead and called tanabe USA. According to them when they did a test fit couple months ago the concept G wasn't fitting right... The medallion fitted fine but they told me that it was not making that much HP... ALSO i was told that they are revising the exhaust and I believe there's another R&D session coming up this month... or end of this month.
Tanabe USA R&D Car Request 370z
^^ R&D thread...