New car?

Hello- I am looking to upgrade my car I currently owe 3k to bank, car value (est) is 20k. Was thinking of selling car, payoff loan obv and taking out a lease on the desired new car with minimum down payment. Was thinking of taking the rest of the money from sale of old car and putting into a cd or something (not sure yet) to let it earn as much interest so when lease is up it will be a decent down payment for purchase. Does this make sense to do? Other option was to trade current car in and buy car now. Credit score is excellent and I would finance through credit union for lowest % Just looking for smartest way to get the new car I would like to get