I can somewhat understand the frustration, it used to be a once a month event to see a wanted ad. But now it's a weekly or even daily occurrence. Perhaps a wanted ad "Frequently Asked Questions" sticky post would help set some boundaries and give some tips / advice for would be S30Z owners?
We have to remember at some point we were all looking for an S30Z or S130Z or Z31 (weird folks that lot ) and didn't have a good feel for the market. Also keep in mind that whilst there is a lot of spammy wanted ads on Gumtree, many folks who have posted wanted ads here have found their cars because other members would rather sell to someone interested, than put an ad out there and deal with all the time vampires etc..
So it works both ways, I think these posts would be a lot more useful if we knew who was asking to buy an S30Z. I know if I was to sell any of mine I'd want them to go to a home where they would be looked after and kept relatively original. Not bogged, flogged, flared and cheap plastic fender mirrored for the latest hipster look... So it helps to know more about the person buying it and how much of an enthusiast they are vs some blow in just going through the latest car faze..