After buying the Zed I put a JDM backbox on it. This turned out to be a mistake as it quite badly emasculated the car's sound (japanese cars seem to run quieter exhausts than UK models).
This problem was resolved at the weekend when I had a Scorpion Y-pipe back system put on it along with a pop-charger.
The noise is, frankly, brilliant. Not too loud so that it sounds OTT, but enough to make a real difference - I think the Zed can take a meaty note without it being obviously aftermarket. I like to things to be "OE+" if you see what I mean and this is just combo is just right IMHO.
After fitting I did the following couple of vids. To be honest the recorded sound does not justify the reality, but I think it's still fairly cool and gives you an idea.
http://350z.junk1.imap.cc/ZedPass1.avi
http://350z.junk1.imap.cc/ZedPass2.avi
I had the work done at http://www.poweritalia.com/ . It's a boutique indy garage near Basildon, Essex who mainly work on Alfa Romeo and BMW. I was originally booked in to have a clicky axle kit fitted but they like a subtle performance mod so when they heard I was planning on having the exhaust done they threw in the fitting for an extra tenner - can't argue with that. They are well worth a look if you live in striking distance...
Shinjuku