See the first version of my autonomous bumper car model. It consists of an own pcb and a 3d-printed body. It is powered via "+"/"-" - lines from a bottom plate which consists of several connected stripboards.
The electric power is transmitted via two wheels, connected to gearmotors, and a carriage bolt. In contrast to most real bumper cars there is no "+"-net at the top! The brain of the car is an ATMEGA32U4 (as used in the LEONARDO and MICRO) programmed via ARDUINO-IDE.
See a more detailed description in the video.
