I have a 2004 Jetta TDI that needs the power steering fluid topped off (about 1/4" low). The local parts store and the local VW mechanic (not a dealership guy) said the car uses a mineral oil for the PS system. The mechanic sold me a greenish colored fluid. The fluid in the car looks to be a clear, almost new motor oil color and smells like the normal power steering fluid that is in my Ford pickup. My question is, what kind of fluid do i need and is this green stuff what I need (and is it even compatible)? Please help - my wife needs the car to go to work in the morning and I don't want her to drive it with the PS fluid low. Thanks in advance.