Even though the W140 isn't the next Mercedes on my list I can't help but look at them since they have come down in price so much. I've looked at a number of nice ones for under $10K. Last week I took a 1999 S600 for a test drive and when I started the vehicle a little light came on just below the speedometer. It was a little wrench and said "-400" and it went off after about 5 seconds. I would assume the vehicle is overdue for some maintenance? Is there any way of telling what maintenance is necessary? The mileage is just over 57,000.