Chris,
I have a car cover made for the Turbo Buicks that I purchased about 10 years ago. I believe I bought it from Kirban. It is light brown in color, has a soft backing to protect the paint and has fitted pockets for the mirrors. It fit the car perfect. I only had it on the car a few times and that was in the garage. It is stored in its on duffle bag today.
(I sold my car a few years ago)
Coincidently I offered to sell it to someone today, but if he does not take it I will let you know.
FYI, it may take a large box to ship it.