Can't add cars to monorail

[Tinchen]

I've been having problems setting up my monorail in the zoo. I got 2 stations that are connected to each other with the "shuttle" option turned on. I can open them and people will ride them, but I can't increase my cars for it. It is stuck at 1 and won't let me change it (Yes, I have closed the stations). Of course 1 car for a zoo with over 4000 visitors isn't enough.

[Altissima]

I might be wrong but I think you have to add more stations, and setting it on the loop would be better.

[Moving Target]

In shuttle mode you can only have ONE car running you can only add more cars if you are using it to travel around the zoo to multiple stations - this is a good tutorial
https://www.youtube.com/watch?v=LnxkmnNBLns
It makes sense that a shuttle service would only use one car otherwise it would meet the second one on the way back lol because the shuttle moves in two directions, travelling only moves in one direction.