Which of the following is NOT considered proof of ownership of a motor vehicle for a Colorado dealer?

The Monroney Label, also known as the window sticker, provides important details about a new vehicle such as its manufacturer's suggested retail price, fuel economy, and standard equipment. However, it does not serve as proof of ownership. Proof of ownership for motor vehicles typically requires documentation that establishes legal ownership, such as a title or certificate of origin that reflects the transfer of ownership from the seller to the buyer.

In contrast, a properly assigned Colorado title establishes ownership for a used vehicle within the state, while an out-of-state title can serve as proof of ownership if it's been appropriately assigned to the dealer. Similarly, the Manufacturer's Certificate of Origin (MCO) functions as proof for new vehicles, indicating that the vehicle is owned by the manufacturer until sold. Thus, while the Monroney Label is vital for informative purposes, it cannot be deemed proof of ownership, making this option the correct answer in this context.