Car radio Code for Opel radios. To determine the Opel radio code, I need the serial number of the radio, starting with the letters BP, GM and RN (see Figure 2-5). It's best to send the serial number before purchasing to ensure that the code really works for you. After a successful check, I will give you the OK to purchase. Fast processing and shipping by email (usually within 10 minutes) Attention: no Siemens VDO models Opel Delco CDR 2005 + CDR 500 GM15001 Opel Delco CDR 2005 + CDR 500 GM1500Y Opel Delco CDR 2005 + CDR 500 GM1500X Opel Delco CDR 2005 + CDR 500 GM02051 Opel Delco CDR 2005 + CDR 500 GM0205Y Opel Delco CDR 2005 + CDR 500 GM0205X Opel R100 Grundig Opel SC 303 Grundig Opel SC804 Grundig Opel SC804 Philips Opel RME Grundig Opel 22DC Philips Opel CCR Philips Opel SV824 Grundig