I was told by a guy last year who has a yellow /yellow Z, that his father in law used to work at GM and said that only about 300 "camaros" were made with this color combination. Obviously, the number of Z's are far less as Z's were about 17% of all production camaros. Obviously, I have no way to verify if this statement is true, but there are not many out there that I have seen.
I am lucky enough to have one myself which I am currently restoring. All numbers matching, fold down rear seat, tilt, POP, and original sales order. It has a Black vinyl top and is an LA car with 55,000 miles.
I have only seen one car that has this color and option combination and I keep up on the camaro market pretty closely
I believe that it is indeed a rare car.