It isn't easy.
The solvents used to soften the carnauba to the point that it can be applied to a vehicle finishare highly flammable.
The companies that make automotive chemicals have all of the proper heat producing appliances and ventilation system to make wax, not to mention that due to the hazard class, the buildings they make the wax in have complete NFPA specifcation fire alarm and fire suppression systems.
What's cheaper... buying wax on line and over the counter or paying to have your home rebuilt after a fire ( if the inusrance company will cover you after they find out what you did)?