| Re: 2003 nav unit
This is a 2003 Pewter Dash CDROM Nav. They were only made for six months before the CTS went to the ebony dash and DVD based Nav. Yes, it will work, but you need to read the Nav retrofit guide over at CadillacFAQ first. You'll need to jumper the VSS signal from behind your instrument panel to a terminal on the Head Unit harness (your current harness will work fine), and have the VIN cleared at a dealer (if the seller didn't do it first), since you'll likely have a 'theftlock activated' screen. | 
2003 nav unit 
