I know a chap around the corner at my work who has fallen ill and hasn't started his Brabus Vito in a year. It looks the same as that E55. The chap is putting it back together now with the help of a local garage and all it needs is brakes, fluids and a bit of a clean. Ill health is just one reason why people sell the cars as they are.
The seller says it starts and runs. I put back and successfully sold a car that stood for 2 years. It started and fired up just as I turned it off. Spark plugs, consumables, belts - they are resilient motors. Now do the same to M156 and it's a financial suicide lol.