So far I've put magnetic couplers on 4 cars> I've been using 2 or 3 motorized units with a magnetic coupler on the rear and no coupler at all up front(for pushing)> Assembling groups of cars on the siding is pretty easy> I've got the one uncoupler pictured below
Disassembling groups of cars is going to be more difficult> It'l require a larger piece of magnet on the motorized unit and at least 2 uncouplers (push the whole group except the lead car past the uncoupler. raise the rod...the larger magnet on the motorized unit will assure the car leaves with the motorized units...at the 2nd uncoupler detach the car... go turn the motorized units around and push it to its destination...repeat...Whew!)
I'm working on schemes for placing uncouplers around the layout (RED "u"s)....the green "c"s are supposed to be cars....go figure