I had the same question when I first got my car. The 01M auto is supposed to be a lifetime transmission and doesn't have a dipstick or readily accessable fill tube. If you want to check the fluid you need to warm the fluid to a specific temp (hence the need for the Vag Com), then take out the plug to see what hapens. If alot of fluid comes out then there was too much in there, and if nothing comes out then there isn't enough. To add fluid, you need to remove a cover plate and screw in a plug when you're done filling. The Bentley guide does a much better job of explaining this than I do, but I think that that's the jist of it. Personally my trans has been working well all along, but did change the fluid and filter at 200,000 miles just to be safe. Haven't had any issues before or after, but I believe that my experiences with this trans aren't necessarily the norm...