I'm new to the site, and am looking for a cheap Z with under 100k miles. Does anybody know of any specific sites that I could use?

 

This is always a good place ot start...

https://my350z.com/forum/cars-for-sale-81/

 

autotrader

 

Auto Trader for one.If you are knowlegeable about cars and have ready cash,Craigslist
is another.I'd check the Atlanta area.You are very close.You will find a great number of
Z's for sale.Also,just do a search for:350Z for sale Atlanta(or GA). A bunch will pop up.
I saw several this week for sale in Ringold,GA...just south of you.