ANY IDES HOW OR WHAT IT NEEDS ? MOTOR? RELAY? WHAT?
THE PASSENGER SIDE WINDOW GOES UP SLOW DOWN NO PROBLEM. on 2002 Audi A6 Quattro
It could be mechanical, but try spraying the window track with silicone spray when the window is in the down position.
Could be a lazy motor or restriction or damage window track seal. May need to remove the door trim panel to inspect or lubricate the window track with heavy duty silicon spray. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online