Car History:2000 GTI VR6 bought used with 28,500 miles on it.No previous records. In the oil filter cartridge housing base and in a small spot visable under the oil cap was sludge. At 29,190 miles GC went in.Drained it today with 2830 miles on it. When I pulled the housing to remove the filter(which looked kinda dirty but nothing big in the pleats)I noticed the sludge that sat at the bottom of housing was gone ! Sample is going out tommorow.