Holy Crap - what the hell is this hanging from underneath my car?

Agree the wishbone looks fine and intact. Not sure what you are looking at there is a wheelarch liner which are made of simple black plastic. It looks metallic, but far too flimsy to have any structural role (as Daz said, if the wishbone was bust you wouldn't be driving the car, full stop). Obviously, though, it's been flapping about and making a nasty noise. When the car's up on a ramp it'll be possible to see where the impact came from that bent it - cos impact there must have been ...

50/50 it'll be a warranty job (or maybe it'll be a 50/50 warranty job :p)