Making custom cards for Hot Wheels Team Transport package?

Has anyone done this? Any suggestions on card stock? Advice on opening without damaging plastic?
I've had a project in mind for a couple of years to make a custom hauler and be able to package it with the appropriate car. Only going to make 2 pieces, one for me and one for the car owner. Thanks in advance for any tips.

https://preview.redd.it/kl8cij42ygtg1.jpg?width=2113&format=pjpg&auto=webp&s=09582dc077190ebf8468e40681a9d7a9f864340c