Car dealership? Worker?

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Hello! I have a question for anyone who works at a car dealership. My dealership has offered a trade in program. My car was purchased brand new last year and has 22,000 miles on it. It’s a 2020 Kia Soul. I would like to trade in for a 2021 kia Nero. My trade in value is around 16,000-18,000. Do I need to have a down payment to trade in on a vehicle that is more than my current vehicle?