I used a vehicle for business and traded it in for another business vehicle in June. I'm having trouble figuring out the deductions for both vehicles.

You purchased your business vehicle as part of a trade-in then and need to handle the trade-in for the old business vehicle. Just to walk through the interview for this trade-in by following these steps:

For your old business vehicle:

1. Go to the Federal Taxes tab
2. Go to Wages and Income
3. Select I'll choose what I work on
4. Click Update on the line for Business Income and Expenses (Sch C)
5. Click Edit on the line for your business
6. Follow the prompts until you come to the page Business Expenses 
   
7. Click Start/Update on the line for Cars, trucks, and other vehicle expenses
8. Click Edit on the line for your old vehicle
9. Indicate that you own the vehicle
10. Follow the prompts until you come to the page Are You Still Using Your vehicle for Business and answer No then enter the date you sold it
11. Follow the prompts until you come to the page Did You Trade in Another Vehicle to Purchase this vehicle?This may be where you have entered that it was purchased as a trade-in. Answer accordingly
12. Follow through the prompts and you will be guided to a page titled Trade-In Link
13. Click on the Edit Trade-In button and make sure the vehicle in the list given is highlighted, then click Delete
14. You will be taken to a Delete Confirmation page and you will answer Yes. This will remove the Form 8824 which is tied to trading in a vehicle
    
15. Follow the prompts to indicate that this vehicle was sold, not traded in, and to enter in any relevant information regarding this sale.