Make sure your pod filter is secured, no oil leaks, all lights working, suspension isn't coilovers, etc.
Make sure the exhaust isn't loud at 4000rpm, as that's where they test it to. If it is, shove a resinator in the line somewhere. $50 fix.
I'm not a fan of BOV's, but if you must run one, have it standard or get a black, stealth one and make sure it's tucked down deep. I had a stealth black one in my old Familia and cops never found it.
Personally, these days, I wouldn't run a after-market BOV. The standard one on the GTR sounds great as it is, and it's 100% legal!
The more 'bling' and chromed piping under the bonnet, the more likely you will get defected. Go the stealth look!