That isn't a sub woofer on the dash it is a dialog (centre)speaker. The sub goes behind the panel in the boot which has a little stowage hole (drivers side). As Tempest says, the sub would require an amp as well.
yep - its a damn good system on the Tempest. Apparently the head unit is very very good quality and the amp and speakers less so, and in america some owners have replaced the amp and speakers with even better ones and the quality is meant to be amazing.
Sorry to be negative here!....but the models that dont get something simple like the front foglights have a different wiring loom to the rest of the models..... so dont expect too much.... but i am often wrong - let us know.