Hatch Area Condition
Sometimes I get insanely bored waiting for parts to come in --- this page is a result of that boredom...but what the heck, maybe this will help someone when looking for a Z.
An important step when looking for or trying to price out a Z is the hatch area condition. Though you will not likely see the condition under the trim panels (as pictured below), you can quickly remove the tool kit, carpet, spare tire trim, and pad (be careful not to rip pad upon removal) to inspect for rust. The most important spots to look at are the low spots (spare tire well and under tool kit). If you see light rust, make sure it's not worse that it looks. Tap on it and see if it's solid. You may see something like pictured below (fixable), or it could be a lot worse. I've seen many pictures of destroyed sheet metal. This doesn't get cheap to fix, and many will tell you that fixes only last a little while. Ideally, you want no rust and no sign of paint corrosion. If you see any and you decide to buy the car, fix it up as soon as possible to prevent further damage.
Here are pictures from my 84 NA. This rust is not yet catastrophic, but needed to be addressed. The hole you see in the tire well just looked like some basic surface rust, but indeed had made it all the way through. I punched out what I could until the metal started resisting just to see how deep it was getting. On the driver side (under tool kit), everything looked like surface rust -- I'll never know (sold the car).
Any sign of corrosion should also be addressed by resealing the tail lights, quarter panel windows, or possibly leaky t-tops. The condition of the tools in the tool kit and formed foam holder itself can also be an indicator. If the tools have white corrosion spots on them, it could indicate moisture has entered. The foam can have mold or feel wet on the bottom side. Also, the cable assembly (for hatch and fuel lid operation) can be inspected. It will all be quite obvious once you pull up the tool kit and remove the spare tire.
Here are some pictures from my (current) 86 Turbo. There was no rust and no sign of water leaking into the car. A good CALIFORNIA find.