It depends on which mileage method you use — if you use the standard mileage rate, a detailing subscription generally isn't separately deductible, but if you use the actual expense method, it can be, as a vehicle maintenance cost tied to keeping your car passenger-ready. The standard mileage rate is built to cover the average cost of operating a vehicle for business use, including routine upkeep like washes and light detailing. If you've chosen that method for the year, you g