I have a 2004 Touring Z. It has a Bose sound system. Recently the subwoofer behind my driver's seat blew.

I'd like to replace this speaker but I do not know what size it is. Can anyone tell me what size speaker comes standard in this model?

 

For the Bose system you're going to want to replace it with an OEM speaker. Check the classifieds here, you should be able to pick one up for cheap.