I bought a MB oem fiber optic cd changer for my 01 clk 430 with bracket and everything. When i connect the plug to it and test to see if it works My head unit says that there is no cd changer. The car doesn't seem to recognize that i put one in, I thought that it was plug and play... anyway does anyone know about this problem? has anyone installed a cd changer themselves. Also does anyone know if i can purchase a command system if it didn't come with the car..