According to the Internet Movie Database (IMDB), in the Man with the Golden Gun Scaramanga’s flying car is meant to have been found "200 miles west of Bangkok", which would actually have put it somewhere off the coast of Burma and nowhere near to James Bond Island.
Added to that the island they end up heading for is said to be about an eight hour sail from Hong Kong. That is at least 1,000 miles from Bangkok in the other direction.
Also of interest is the fact the movie was nearly made in Cambodia a few years earlier but had to be postponed due to the Vietnam War. Had that terrible conflict never happened perhaps it would be some island in Cambodia that would have benefited from the millions of dollars in extra tourism.