What to look for when buying used?
 

For sale ads....

Good service records. The Z car isn't any different from any other car so the usual stuff.... leaks, grinds, unusual noises, vibrations; anything that doesn't feel right. Once you've narrowed it down, make sure you can get a PPI from a Nissan dealer or independent specialist. That's really the only way you're going to be REALATIVELY assured of a decent car (or at least know what you're getting into.) A $7k budget is going to mean higher mileage so that is even more important.

If the seller balks at this, W-A-L-K.

Certain models have their foibles but you can find those all listed here on this forum.

Why do so many new members post in the forum feedback section.