I found a bug, which should be easy to fix. When the vehicle is auto-upgraded, all the cargo it was carrying is disappearing. This creates problems if there are lines that are supposed to pick it up – jams, money loss.
Also, if I may, I would ask for a couple of small tweaks to auto upgrade:
1) Add option to upgrade at 0% age (or 1%, whatever) — to be able to force update whole line to a new vehicle type. Otherwise a lot of manual work needed to track the vehicles that were purchased recently.
2) Add an option to auto upgrade to Empty vehicle – basically deliver the cargo and sell all vehicles on the line. Might be useful to shut off a line without losing money it carries on board.
I really hope this can be implemented 🙂
Btw, I’m currently spending a week in a See Spital in Horgen, your game helps me from dying of boredom 🙂