The Divider Switch
In the trunk, you have a divider that you can put up to "reserve" space in the trunk for the convertible top to store in while it's down. It would be a bad day to put the top down when there was anything in the way of the top's travel. To stop you from putting the top down in such cases, there is a switch in the trunk that tells the PTCM that the divider is up. If that switch does not indicate the divider is in position, the top won't go down. (Not a bad idea, but unfortunately, probably the most common failure of the top system is the failure of either the divider switch OR, failure of the divider rod to properly activate the switch!)
Here is a look at where the switch is, the arrow points to the switch, but the switch is not visible in this photograph.
Here you can see PART of the switch. Note the shiny metal leaf, the rod from the divider has to press, essentially, UP on that leaf in the direction of that big round trim plug. The little white '****" you see above the leaf is the button that the leaf presses on. When that little button is pressed, the divider switch is 'active' or 'closed'. Can you now see why the divider switch can easily fail to indicate that the divider is up? (If you missed it, there is a very good photo of the divider switch in post 1, at the very bottom of the post, with all the trim panels removed.)
There is much more to learn about this switch, but first, we must talk about another switch.