I can't help wondering why its so cheap. CLS55's of this year and mileage usually command a price closer to £9-10k
And the owner is dreaming if he thinks 650bhp is easily and inexpensively achieved. 600bhp yes, but then it gets a lot dearer on a 55K engine.
Love that even on the AMG W219s the default dash was proper wood rather than the current blind you if the sun is out aluminium trim or 1990s Ikea black ash wood which seem to be the only options in current large MBs.
Looks an excellent car for the money if it checks out but would prefer silver wheels as another poster said.