How do you add transmission fluid in a 2000 VW Jetta and where is it located?

For an AT, here are most of the main steps:

You can do it yourself but will need to have a few tools, and will need to raise the car "evenly", so both front and back are raised. *Critical tools to have: Torque wrench, Metric socket set, Allen wrench (strongly suggest socket based so you can torque it correctly later), oil drain container, 2 jacks (2ton or more), 4 ramps and (not to lift, but just for support.. i just slid them underneath after jacking the car evenly from both sides (get a friend to help), 4 jack stands,for additional SAFETY!!!

Before doing anything else, download the 311 or 409 version of this software for older vw's, or the newer version for new ones:(probably torrent, etc) http://www.ross-tech.com/vag-com/download/

You will basically need to buy a compatible cable, plug into your diagnostic port on your car (under the steering wheel), then to the serial port on your PC (any old PC will do), and use the software.

Before starting as well, run the software, then go to ross-tech.com to get the code for the software so you can read the temperature on the tranny so you can get an idea of what your going to be doing.

Follow these steps for starters: http://www.blauparts.com/vw/vw_fluid/vw_automatic_transmission_fluid.shtml

Also visit the forums from vwvortex.com for further assistance.