I looked a '82 ZX today and I liked a lot of things about it but one. It doesn't run but that does not concern me. It has minimal rust, headliner is falling. Here's the rub, both floorboards are wet and it smells musty inside.

I've owned a 280zx that leaked after a new windshield install. I currently own a 280z that leaked from the cowl rust around the intake chimney.

Question. What is the most likely location of leak on one of these? One clue could be the forward edge of the dash is surface rusty.

The price is right but I don't want to rebuild another cowl.

I appreciate any input. 

If it’s a t-top then those seals love to leak. Windshield I’ve also seen as a common spot, especially on top where you’ll notice some bubbling around tge windshield seal. If slick top then windshield or possibly where the door window seals at the top.

It is a T-top. Do the floors get wet from them leaking?  Is the cowl rusting out a common problem like in an S30?

Floors can get wet from several causes, but from my experience the t-top seals are most problematic. I don’t know how common the s130 cowls rust out but I have yet to come across one after messing with several. Should be relatively easy to remove the screws from the black plastic trim on the cowl, open it up and have a look inside if it’s a potential deal breaker for you.