The law is very clear on this. You can build a Lambo, or a Ferrari, or anything else, and you can call it anything you want, and you can badge it any way you want. As long as it is for your personnel use, you are fine. If you sell it, then you have violated the Lanham Act and committed a Federal Crime. I am absolutely certain of this, but before I embarked on a $100,000 journey, I would get my legal information from anywhere except an Internet Forum.