As SLUsager notes, you should try for what you really want to do. IMHO, the last thing you want to think on your deathbed is, "I should have done specialty X, but I didn't even try" (hopefully, you're thinking about other things at that time...but for the sake of argument...).
So while Plastics, Derm, ENT, Ortho etc may be effectively closed to FMGs, if you don't try you will never know whether or not you could have gotten a spot. That said, you need to be realistic. Plastics for example, usually matches 1 FMG each year...and those guys are pretty spectacular.
Do what you want but have a back up plan if Plan A doesn't work out for you.