I have a 1998 SL and it has a very slight drip from the Autogearbox unit. I have taken it to my local Mercedes Specialist Repairer and looked at it underneath on the ramp and he thinks it is from the of gearbox casing where the electrical connections enter the gearbox. It is only a very minor leak about two drips a week and he tells me it is unlikely to be sufficient to loose enough oil between services to need toping up but it will make a mess on my driveway. He says that the seal to the unit can only be replaced by stripping down the whole unit and that is a major cost - £1800-£2000 so best to live with it. Has anyone had such a problem and is it worth trying to seal it with silicone from the outside ? The car has done a genuine 43,000 miles from new.