Installation Dension Gateway 500 in SL R230 BJ 2006

Hello everyone, I bought myself a SL500 with the year 2006 and would like to install the above-mentioned iPod interface with Bluetooth adapter. With my previous SLK I have had the Comand Gateway in the passenger footroom, but is located in the SL of the BOSE Subwoofer, so now the question is where can I find the control unit for the Comand or do I have to pull the Comand forward? I thank you already in advance for your help. e and wish sunny greetings from Hamburg, Andrzej