I am buying a second car, used from a private party. I will be using it about 90% of the time for work, having to drive to and from work sites. I know about the standard mileage deduction, but I just had to get some work done so the car would be safe to drive (i.e. brake job, motor mounts, oil change). Can I deduct the cost of those repairs, insurance payment, gas receipts at 90%? What about the purchase price of the car, is that deductible?