I had a small project of building and designing a parallel parking car with infrared sensors around the shell.
I decided to build a small model car, which was essentially just the base of the car with a plastic top to hold all the parts together.
Above is a picture of the 3D rendered model that was printed (minus the wheels and the motors). The overall project had a few different parts so that it wasn't too difficult to do all in one print and then attached together to construct the core of the car.
It took a few times to get the correct sizing for the 3D prints and the housing to fit with all the servos, sensors and motors for the car.