I appreciate that many have cars on here with 100k miles plus. But to say high mileage isn't a issue is just wrong.
It will obviously impact future resale and the engine is much more likely to fail. The same as every other car.
Even big engined German diesels (535d, 3.0tdi) with 100k + are very difficult to sell and are £1000's cheaper than lower mileage equivalents.
It's fair to say that a z with over 100k miles is likely to have a few problems.
I remember when I first joined and a guy was trying to sell his "perfect" 100,000 mile 350z to every new member. I remember one guy buying it a the clutch failing on his journey home. If I remember right, it had other issues as well.
If you are buying a 100k mile car. Have it thoroughly checked over.