What happens to my deduction if I stop using the car for business?

If you claimed Section 179 on a purchased vehicle and business use drops below 50%, you may have to recapture (repay) a portion of the deduction. A lease does not avoid the issue: if business use of a leased car drops to 50% or less, you generally must add an inclusion amount to income (IRS Publication 463). Ask your tax advisor before your business use changes.