it is my guess that they get 'pushed' thru the brick or just gravity alone takes them through..
tthere is a bit of a bug with minecarts now not stopping if you end a track in cobble stone... may be similar to this.
I do believe we can come up with a water system and redo the distribution levers by wiring track switches to a common circuit
if we wanted to do this in an intelligent-like fashion, we need simply to map out a 'flow chart' /logic diagram for the inputs and outputs that we want, then make room for each logic gate in a modular fashion... space per circuit per logic gate in the diagram....it really is all modular... just so long as you connect the right outputs to the right inputs etc
