How do I count a vehicle used for job and business related travel that I leased for half the year, then bought out the leaser and now own \the vehicle?

Enter the vehicle as a leased vehicle used for business, then when it changed from leased to owned, you will need to report that the leased vehicle was converted to personal use and enter the same vehicle purchased as a new vehicle. 

When you enter the vehicle as a new purchase, you will be able to use Bonus Depreciation if you so desire, that would not be allowed for the vehicle when it was being leased.