Q. Should I consider this as exchange or trade in?
A. It's a sale of the car, a personal asset.
Q. How I deduct the loss ?
A. You don't get a deduction on the loss on the sale of a personal asset. All your business deductions are already included in the mileage allowance you previously claimed. Even if you claimed "actual expenses"instead of the mileage, the depreciation you claimed is the only deduction allowed.
