Blackmirror- You have a "cult car" there, so many of your serious prospects are PROBABLY gonna REALLY know their stuff about it. That's generally good for you. *I* wouldn't worry much about guys who DON'T really know their GN's- market it to the experts.
Some likely Q's (besides the obvious) are: original paint/repaint, any accident damage, any chips/hazing on windshield, is it stock or souped up, has it been to the drag strip, do you have the maintenance records and or ownership docs (manual, window sticker), what tires are on it, stereo OE or aftermarket, any holes cut in vehicle (extra antennas, etc.), any other changes from stock, will it pass emissions tests. You might also get some Q's about how you treat it, especially as it's turbo- do you do a cool-down before shutting it off, what oil do you use, do you ever use it for short trips (no warmup), etc.
Check out Hemmings, etc. and see what GN's are going for these days. Base your price on the going rate and DON'T get anxious and let it go too fast, too cheaply. That's gonna be, IMO, a good car to be putting on the market. There's ALWAYS a demand for *NICE* GN's.
Advertise in Hemmings, and any GN Club publications, and maybe, if it's REALLY nice, the Dupont Registery. Also the online equivalents. Try to reach the serious, GN-experts-with-money prospects- they're worth waiting for and will appreciate a nice one. And they really ARE out there.
Don't get defensive/stressed if/when they show up and start picking the car apart, that's just part of the process. *I'VE* picked cars apart so badly that the owner was ready to kill me (heh heh, even though I was nice and polite about it) and when he expected me to walk away, I instead payed his asking price.