First of all, a big "THANK YOU" to all developers, artists and other contributors for such a great game!
I'd like to suggest a little change of the auto-spreading feature for shared timetables. Currently, it works very nicely for vehicles with active timetable, but seems to behave a bit weird for vehicles with inactive timetable. If several vehicles with still inactive timetable are waiting in a depot, the auto-spreading feature gives the earliest start date to the last vehicle in the queue. And if one sets the first vehicle's start date to something in the very near future, the other vehicles even get start dates in the past. It seems more useful to me, if it was the other way round (earliest start date for the first vehicle and later start dates farther back in the queue). And I think I'm not alone in this opinion: http://www.tt-forums.net/viewtopic.php?f=31&t=72783
I'd also like to suggest another little feature. Currently, if I start one-by-one some vehicles that are waiting in a depot, then they leave the depot in a more or less random order (unless I wait for each vehicle until the previous one left the depot). It would be nice to have vehicles always leave the depot in the same order as I started them.