Generally, Ford Mustang enthusiasts don't have a lot to complain about. The Mustang is available in many trim levels, and when you see one on the streets, you'll know it. There are, however, always the "what if it had..." and "wouldn't it be cool if the spoiler looked like this" moments. It's not that every Ford Mustang hasn't been sheer genius. It's that creative car enthusiasts can't help…