Une bagnole is a common slang word for “car”.
Son mec s’intéresse qu’aux bagnoles.
Her boyfriend is interested only in cars.
Je me suis acheté une nouvelle bagnole.
I bought a new car.
Note that the usual, non-colloquial word for “car”, une voiture, is also frequent in colloquial French. Une automobile is too formal and une auto is quite uncommon (it sounds a little old-fashioned to me).
Two other slang words are une caisse (which usually means “crate”, “box” or “cash register”) and une tire. They are a little less common than bagnole.
Alors, tu la bouges, ta caisse ?
Move your damn car! (You may hear this sentence from angry drivers in traffic jams.)
Here are a few other car-related words. The French words for traffic jams are un embouteillage (not colloquial) and des bouchons (slightly colloquial, but you may hear it in non-colloquial situations). The primary meaning of un bouchon is “cork”.
There is a very busy ring road around Paris officially called boulevard périphérique. Nobody calls it this way, though, people say le périphérique, or just le périph.
Y a encore des bouchons sur le périph.
The ring road is jammed again.
Listen to the examples: