Does 2007 mercedes benz cls550 have an auxillary battery and where is it locate

Not all do. Call a Mercedes Benz dealership and talk to the parts department. Give them the last 8 digits of your Vin#. This will tell you weather you have one or not. This drove me nuts! I bought an auxiliary battery for my 2007 CLS550 and every uTube tutorial I watched showed how to install the auxiliary battery. I took off the cabin filter housing and the fuse box housing in the engine compartment. My manual even stated that my vehicle had an auxiliary battery located in the engine compartment. Well I finally called the MB dealer the parts man didn’t have a diagram of my 2007 CLS550 so he asked me for the last 8 of my vin# and told me that my particular model CLS550 on has the 1 battery in the trunk. The answer to your question is “NO” all 2007 CLS550 do not have an auxiliary battery! I hope this helps you and anyone else who comes across this mind consuming nightmare.