Hey guys,
I'm only writing this since I had this problem and now a mate with an R32 has the same thing.
Ever since I imported my car there has been a fairly pronounced fuel smell all the time. I put this down to rich mixtures as my Silvia had the same thing.
Recenty when I filled up my car it started peeing itself everywhere. I thought it was the compliance restrictor but turns out no.
On the top right of the fuel tank looking from the back there is a vent hose just behind the main filling pipe. This was perished beyond a joke on my car and was leaking like a siv.
To access the pipe you need to take off the right rear wheel and the plastic liner on the left hand side of the wheel arch that covers the fuel filler pipe. You'll see the vent hose that leads to the top near the filler and thento the top of the tank.
Take off the crappy hose gripper things and bin them. Take off the pipe and measure it against a pipe at Repco/supercheap whatever. I used the heater hose off an old falcon. Not a perfect fit but good enough.
Also buy two decent hose clamps. Cut the pipe to length and install over the lips at both ends. The filler side is easy to attach and tighten up however the nipple is only plastic so don't go crazy tightening it up. The tank side is a bit harder, requiring monkey arms or two people.
To get access to be able to do up the fuel tank side hose clamp you need to open the boot, take off the little liner door on the right and reach down, you'll feel a plastic boot vent. There are two 10mm nuts holfing this on at the top and some nasty black sealant. Once the nuts are off, jimmy the vent with a screw driver till it comes off. WATCH THE BOOT LINING! The black stuff is sticky as hell.
Now with someone on the floor holding the clamp from the bottom you should be able to get a socket screw driver (don't use a regular flat head) onto the clamp going in throught the hole made by the missing vent. Its a metal nipple so do it up quite tight to prevent leakage.
Replace all your lining and stuff, check the filler hose to see if that is okay (mine was fine) and your done!
Enjoy your new smell free car.