There is another spoiler option: fabricate your own. Start with a little modeling clay and consider the existing fender lines. Try to blend the sail panel with the fender lines. Consider how the factory might have done it if they had done it. And find a skilled craftsman to work the metal.

Fixitman

Nice work Fixitman!

Here's the offering from the 73/12 HS30 Sports Options Catalog available to the homemarket. Part #98100-E8276 was a 3 piece version that was available. It looks like it is predrilled for attachment? Not a good scan, but another to add to the list.