Well, a lady in Jamestown, New York, had a 1978 Marquis. It's basically the same car as McGarrett's, except that hers had a B-pillar (column between the front and back seats). Ever since she gave up her car, she has wished she had it back. Her children went in together, found one just like hers, and restored it, down to detailing work on the exterior. They presented it to her on her birthday. Her reaction is priceless! Watch it on YouTube:
Here's an outstanding video about an actual '74 Marquis Brougham, like McGarrett's (except for color). The man who made the video even referenced McGarrett's car. 1974 Mercury Marquis Brougham 460-4V Hardtop Walkaround & Drive: The Hawaii 5-0 Car - YouTube