I purchased a 2007 ML350. I took it to a qualified repair garage for a wheel sensor job. After paying my bill, the car, parked in the garage lot, would not start. They jump started it, and I drove it a few miles to increase the charge. It stayed in my driveway, and then the battery was again dead. Indications are that a battery in this model does not last long. User's recommendation: This model may have frequent battery problems, according to online reports that I've read.