Motor cars & trailer cars

The OpenBVE.api gets the total number of cars, although Train.dat specifies them as motor cars and trailer cars. Why not keep them separate in the .api for more flexible use in the plugins? I made trains which can have one or two locomotives and that could be retrieved directly from the train.dat file by the plugin, instead of creating an entry in the plugin config. Another related issue is when trains have a loco on each end (take the TGV, for instance, or the Freccia Rossa): there is not a way to tell that one of the locos is the tail car, if the consist is greater than 2 cars (from inside the cab perspective). This is valid also for push-pull trains when running pushing. I've tried different settings and all the engine sounds can be heard inside the cab, even when the loco is the tail car. If we look at US freight trains, some of them have multi-loco traction with locomotives in the middle of the train.
The idea is to indicate the motor units position along the whole train, so the sound can be emitted from each loco and heard inside the cab only if the cab is located in a motor unit.