This is lovely. I take it you used the original Headmaster body, and replaced/repainted the Siren head by unscrewing both?
Yessss. HasTak would be insane if they didn't do this at some point, but I doubt it'll look this good. Siren next?
I bet Hasbro will do a Streetwise-level retool of the car body and chest plate if this gets made, but, daaaaamn. Nice job. My only complaint is that the flames seem a little... Off? In a way I can't really pinpoint but fantastic job nonetheless.