Can someone explain to me what the Business Tax Benefit means in the cost of ownership calculator? I always see nice cars with commercial plates and I just wanted to see how I can get in on that. My wife has her own business, albeit a break even endeavor. I also generate some consulting income in addition to my salary job and being classified as a "pattern day trader" by the IRS. I have always done my own taxes because of the day trading complexity, but this was the first year I had to cover a business as well. I just feel like I'm missing something in regards to deducting vehicle use. Maybe it's time to have a pro do my taxes!