If you set up/entered the vehicle as an asset, you would use the Form 4562 Depreciation and Amortization Report and Form 4562 Alternative Minimum Tax Depreciation Report. I added screenshots to my answer. Note: these reports are not sent to the IRS so when you print them, they'll be part of general reports and schedules (not reports required for filing). If you don't have these reports, use the calculation in my answer.
