Christmas Rail Car 7

This is rail car number seven in what (I hope) will be a series of ten, one published every two weeks until Christmas. This O gauge car (wheels, axle, coupler and bed are all 3D printed plastic) is part of an active train.
First, you must build "Motorized Perseverance" by gzumwalt
http://www.thingiverse.com/thing:445919
This will keep you busy for a while. Next add the wheels, base and wheel carrier to hold "Motorized Perseverance."
This is high profile, so clear out any low hanging br