Unable to add new car to input the buying price, taxes involved, and work expenses for vehicle. How do I do this?

Bought a car from a dealership, I have a statement that includes the sales tax. Additionally, I put that I stopped using a previous vehicle which was around the time I bought the new vehicle. However, on the vehicle summary page I am unable to input the taxes and work expenses even though I put this car as a fee under car registration. How do I get this vehicle added to this tax file?