Batteries for the main key with radio wave remote control, removing and installing: Notes
WARNING: This page does not describe the selected car, but rather 26 other vehicles, including the 2009 Volkswagen Jetta, 2008 Volkswagen Jetta, 2007 Volkswagen Jetta, 2006 Volkswagen Golf, and 2006 Volkswagen GTI. However, it is still accessible from the selected car via links, so may be relevant.
1 1 - Transmitter unit - upper part (turned-over)
2 2 - Key battery
3 3 - Contact plate
4 4 - Key battery
5 5 - Transmitter unit - lower part
6 6 - Main key with variable code transponder
To be able to differentiate between a key with transponder and a key with variable code transponder the main key has a "w" stamped on it.