While I think it's great that the Fastback finally gets a bit of love with bodykits, IMO most of it is overdone. The N is an understatement, not a gold-wrapped C63 AMG... If there was a bodykit that's more focused on being a bit of an understatement while still looking quite brutal.
A not too large rear wing maybe in combination with an actually functioning diffuser and perhaps some modifications to the front would be perfect. But hey, everybody to their own.