This is what I found regarding Section 179 as it relates to small vehicles purchased for business.
Small vehicles.
Millions of small businesses and solo business owners use small vehicles on a daily basis. These include passenger cars, crossovers, and small utility trucks. Small vehicles that weigh under 6,000 pounds have a Section 179 deduction limit of $10,100 in the first year they are used, and $18,100 with
bonus depreciation.
If the vehicle is not used 100% of the time for business, the deduction allowance is reduced proportionately. For example, if a florist purchases a van that is used 50% for business purposes, the limit is $5,050 ($10,100 x .50).