here are some cutoms i wanted to show

I made and engine powered Emily I used a flat drive unit that was heavily cut to fit and got some wires to use on the model 

the back 

the wires 

and the flat drive unit inside I hot glued the axel of the front wheel and added 2 weights on the front that fit and a weight at the back I might use wires that can move more freely but not now. works well but can go up hill. 

Thomas but better I got the non working rc Thomas added a unit from a Percy and the switch fits and a metal bit that makes it run 

back

and the unit. Its a sandwich fit as I have to go through the model to close it but works. I decided to give it a spare tomy Thomas face.