If you guys want to wait , i will have a scenarios pack update on the F real soon featuring the F via the A and C to Euclid or Lefferts, with the proper announcements.
If you want to modify it yourself for private use , you can open up the desired route file and change the location and name of the Departure and arrival sound
EX :
.sta 207th Street;11.2800;11.2830;0;1;1;ats;;10;50;\A\207th_dep.wav,
Arrival sound :
,.Announce 190_arr.wav,
. The new code you put in must link up to the sound folder in the sound directory EX: Sound/A1/190_arr.wav