Rover Chassis was added in release 18 The Detailing Update, it's mostly for having fun and messing around, driving around the moon / planet.
Appearance[]
It has a long chassis and 4 wheels with texture.
Gameplay[]
You could make a flying rover attaching control panel on Rover Chassis.
It can drive up to 40 kph on Mars, it may vary on the gravity.
For some reason you can make all parts get flung with Rover Chassis in building mode.