[JensenS3]

In the cargo area, there is a switch panel with three switches. Two are for the optional power fold-down rear seats. the third one, on the bottom, usually shows as a switch blank, but pictures of European models usually show a switch there as well. What is it for?

 

[MichelR]

It is to release the tow hook..

When you press the button the tow hook is release and you can pull it into place to lock it.
When you press again the took hook is unlocked and you can push it back up into it's hidden position.