Very nice & clean. A couple of suggestions:
I think the rear diffuser would look better without the gap above rear fog. Looks like it's missing or broken.
The stripe is cut too short at the wheelwells. It should have been made a bit longer so it wraps around the entire edge (you can notice this in the pic of the front wheelwell).
Also, can you legally advertise/use the name 370z GT since Nissan already has that model in the UK?
2011 Nissan 370Z GT | car review @ Top Speed