Selling car used partially for business--traded-in multiple times in previous years

I have a car used partially for business in previous years that I sold in 2020.  Hasn't been used for business since 2015. I am retired now.   In previous years, other cars used partially for business were traded in, finally resulting in this car I just sold.  Each trade-in was recorded on a Form 8824.  I used the standard mileage rate on business miles.  How do I now record this sale of the car in Turbo Tax??  How do I calculate the adjusted basis?  Depreciation?  Business versus personal?