I purchased a 2001 GLS with 64K. It has automatic with the 2.0 gas engine, code AVH. It seems to run fairly well. I want to change the transmission fluid immediately in order to help the transmission live for as long as possible. Is there a synthetic fluid that will help in longevity, that is without doubt compatible with the transmission. I do not think that the official VW tran fluid is synthetic, so I would not put synthetic in unless I know that it is 100% compatible with VW engineering. Can anybody help me here? Much thanks.