Hi Noel,

We wouldn't be worried about the battery at all at this stage; it's still very new and batteries are very reliable anyway. It should still be under warranty, in fact. That S-Class is known to suffer with issues in its rear air suspension that could be costly to repair, so listen out for rattling/clattering from the rear as you drive along. Other than that, the car is too new to have widely reported issues. That's obviously quite high mileage already so make sure servicing was done to schedule and have the car checked over meticulously by someone that knows what they're doing.