Puddle in the car
 

So I was cleaning out the back of my 81 N/A 2+2, and I moved the panel that hides the spare, to see if there was anything that had fallen back there. Much to my surprise there was a puddle with maybe an inch and a half deep where the spare is. I mopped it up best I could, but I can't figure out how the water got in there. The weatherstripping in the back looks good, and I couldn't see any place where it really would have gotten in. How common is this problem? Are leak-prone areas that I should look for?

It's either from the hatch weather stripping, or wheel well. There's a rubber plug at the bottom, you can yank it and keep the water from building up.

The rear quarter window can leak as well and pool up back there... It is a common problem and one of the first places I check for rust....

Thanks guys! So I checked the weatherstripping around the hatch and window again, and they looked fine. However, I checked the rear quarter windows, and they did look like there had been some water leakage there. I'm going to try to build up the weatherstripping with some gasket builder.

and its not in the back back area right? the area behind the spare, with my car it had a good amount of water build up in there when i first got, it freaked me out too when i blindly reached my hand in there for the first time. It was because the metal around the side light was warped from a collision, which caused it to not seal, making a lot of water leak in, luckily i caught it before it started to rust,

I think it's a butyl sealer they use back there. I think the key is to get rid of any slime that will keep it from adhereing when you remove the window and the old sealer....

Also check the weather stripping on the rear tail lights. That's where mine is leaking. Those are a lot cheaper than the hatch weather stripping.