Respect you for being upfront and honest, it's more likely going to help than hinder. You'll end up sifting out a few tyre kickers.
Like it has been mentioned, it's only been 3 days and the hottest weekend we've had. You've also chosen a weekend of sports and car shows so you won't get attention today but you may get people like me, who saw the car at a car show and started looking not too long after.
Make sure you've got plenty of photos and details in the ad and you'll have less enquirers but more of a serious mindset. Just note the 350z and 370z are a very particular taste, especially with the lack of turbos and the road tax rate.
Good luck with the sale!