Just an FYI for those who own 80's to early 90's 300 series cars. I am taking out the Becker radio and installing an aftermarket radio. I did not have the code in case I needed to put the factory Becker radio back in. I called the local dealership with the radio serial/car vin and the guy told me that through the 89 model, there was no codes to put in as a consumer. These cars are required to let the dealership hook a special tool and program it. My dealer said they charged $15 to do it. He said starting in 1990, you have to have a specific code to enter. This is just FYI for those who have questions like I did.