The base is fitted to a bed like the ender 3, it is recommended to use a base of the materials you have available to save time and material.
For the other objects you can scale them to 35% to look like in the pictures or choose the size depending on your base.
Hollowed out ball, made in two parts.
The car is printed in 12 parts, designed to respect each part of the model and with comfort in mind when printing
The dome is optional and is assembled by printing 5 units of the file "half hexagon" and 15 units of the file "hexagon for the dome".