In Australia, a "chick magnet" is a large attention seeking car owned by a young guy. It is intended to attract girls (chicks). It always has a serious stereo, and probably has a modified exhaust.

Young guys spend a fortune on their "chick magnet", presumably to indicate that they could spend a fortune on potential girlfriends. The desired outcome often fails to eventuate - many "chick magnets" are only driven up and down the main street occupied by the single owner and his single friends ;)

On a somewhat related note, the process performed to separate hatchlings into roosters and pullets is called chick sexing.