How to use the door announcements with hotkeys?
The problem is, that if you play the door announcement (with hotkey or on second screen by clicking), you leave the list of the normal route announcements. 
You can't just click on "play next sound" (e.g. via hotkey), because the next sound of the door announcement list would be played, since this is the list where the last sound was played.
To solve this problem, you need to save the place in the list with the normal route announcements, where you are (usually in this case it would be the "next stop: xxx" announcement, 
which you play before announcing the exit side). A way to save the place is by marking the announcement, since that is independent to the played sound. 
Go to Settings and set the hotkey for "mark next sound". Then set another hotkey for "play marked sound". Then you can start your drive. 
But don't forget to keep pressing "mark next sound" when playing the next sound in the list. 
The marked sound should always be the sound you will play next (example: just left Koblenz, you play the greeting announcement and press "mark next sound" so the announcement for the next station Rhens is marked.) 
Then, if you arrive at a station (in this example it is Rhens) and want to do the door announcement (now the greeting announcement which is played after leaving that station should be marked), 
just press your hotkey for the door announcement. 
After leaving the station, simply press the hotkey for "play marked sound" and you are back in the announcement list. From now on, pressing "play next sound in list" will play the next announcement since you returned back to the list. 
Repeat that steps every time you want to play an announcement that is not part of the route announcement list (e.g. Special announcements, door announcements).


Example:

"next stop: Rhens"
-mark the greeting announcement, should normally be the announcement after the one for Rhens-
press the hotkey for the exit direction
"exit on the left/right"
-after leaving the station: press hotkey for play marked sound-
"welcome on board ..."

Repeat that every time