Tonight I bought a black 1990 RX7 Convertible and even though I thought it was perfect my passenger is getting wet feet from a interrmittent under dash drip. Can anybody diagnose the first of what I'm sure are many problems to follow?

Thanks and good to be back in a real sports car!

 

I'm assuming its not raining, and warm outside so you're running the air conditioning. The drain to the AC is probably plugged up and its emptying the only place it can, onto your friend's feet.