What's this thingy dangling from the front of my car?

Pictures here, here, and here.

The car’s an Opel (Vauxhall) Astra F, built in '97 or thereabouts. As you can see in the last pic, there’s some damage to the (left) fog lamp, so perhaps there’s some connection, though I don’t recall even a minor collision or something else that could’ve caused the damage.

The dangling part itself seems to have no obvious metal connectors, and the car’s operation appears normal. Any ideas?

It looks like its the lamp socket for the broken fog lamp in the third picture.

It’s a lamp socket for sure. Tape it up so it doesn’t get ground off while you drive, and short your lighting system in the process.

Clearly, your flux capacitor has been stolen.