2003 - 2004 - 2005 - 2006 - 2007 Cadillac SRX & CTS AM FM CD Cassette Player Radio. Part Number: 25741528 Option Code: U2S. This is for a factory OEM Cadillac AM FM CD Cassette radio used in CTS & SRX vehicles between 2003 and 2007. This radio is being sold as a REPLACEMENT ONLY! Cadillac radios utilize a data stream and are not able to be upgraded. If you do not have this exact part number currently in your vehicle, it will likely NOT WORK. If you are unsure of your part number, give a GM dealer a call with your VIN and they should be able to provide you with the correct part number. Please Note: After installation, this radio will need unlocked by a GM dealer. Most charge around $50 but depending on where you live, it may be more. Please make plans before purchase and feel free to call around for the best price. It is a 5 minute process so don't let them tell you differently!