If you are using TurboTax Online, on the page where you entered the disposition of the old car, make sure to check off YES to answer the question. “If you sold the vehicle during the year, do all Capital Cost Allowance Chart amounts above apply to a single vehicle, and the CCA class is now empty?”.
For the new car, as it is leased, you would not take CCA on it. Enter it as a separate vehicle from the old car, and instead of filling out the CCA section, you would fill out the “Leasing cost for vehicle” section.