amplifier

Hi all, I've done a lot of searching forums etc trying to find a solution to this over the past few months. I've wired a fair few subwoofers myself in old cars etc, but cannot figure this one out as swapping the head unit in the Astra J is so expensive. I'd like to get a subwoofer and amp...

Hi I currently have a 2007 Astra H with a standard head unit / sat nav built in. I was wondering if anybody know's if there are connections on the back of the head unit for fitting a subwoofer? It is a 1.8 Astra Club. Thanks