In your case, you won’t have to worry about this because spot deliveries are illegal in Colorado and considered auto fraud.
That said if you ever buy a car in another state, spot delivery might be legal there. Spot deliveries allow you to take the car home before receiving an answer from the lender. Unfortunately, if your loan application is declined, you’ll be asked to bring the car back. The dealership will submit a new loan application and it may return with unfavorable financing terms.
Spot deliveries often happen when the dealer knows you won’t be approved at the rates you cited. After your application declines, they’ll ask you for a cosigner, higher monthly payment, higher sales price, or higher interest rate. Because you’ve already driven the car home, you’re less likely to return the car and dealers are more likely to make a profit off of you.