If you sell a car on ebay to a buyer in the same state, what taxes do both parties have to pay and to whom?

Question

As a response to Judy, what would constitute a profit?

E.g., buyer originally purchased car for $5000, sells a year later for $4000 (car just sat in garage during that period). Would there be zero profit, or $4000 income?

Answer 1

The seller (private party) does not pay taxes. The buyer pays state sales tax on purchase price during the registration of title.
point 2. If you (private party) buy a car for 5000.00 and sell it a year later for 4000.00, there is no income, no profit.
My opinion, and belief.

Answer 2

The buyer would pay sales tax when they register the car.

If the seller sold it for a profit, then the seller would have to pay income taxes.