Anyone from engineering here?

Would like to know how seniors build the egg car for the catapult..
Any ideas and advices would be appreciated!
Currently brain stucked and very stress

These are the competition details:
Objective
Design and build a "vehicle" that is powered only by one standard rubber band to transport a raw chicken egg the greatest possible horizontal displacement without breaking the egg.
Rules
1. The vehicle must be constructed from basic components. The components, however, cannot be parts from toy cars. Otherwise, there is no restriction on the material that could be used for the vehicle.
2. The vehicle must not have any parts that can rotate. The egg must not rotate also while the vehicle is moving and must remain on the vehicle so you might want to use a "seatbelt" for the egg.
3. You must design and construct your own catapult using only one standard rubber band. The rubber band may be cut but it may not be treated with chemicals or heated or cooled.
4. The vehicle must be launched using a catapult.
5. The catapult with the rubber band must be anchored to the ground at the starting point.
6. You are not allowed to use any lubricant in the form of liquid (including ice) or powder for test-runs.
7. Displacement will be measured relative to the centre point of the egg.