Hello id request you to open my patreon link which is free scroll down to the second last post "Learn to modify addons to your need" i have given detailed instruction on how to change the colours of you car if you need any help lmk :)
to use addons you need to have cheats on its better to use the /summon command in the chat box than having a crafting system since A these cars are designed for servers where the admin controls access or B it would be hard to make a crafting recipe uniqe to each car and would require custom parts such as wheels engine and items that cant do much alone yet would take server space..
AE101 GT ?