Auto depreciation

[christygunther]

I traded in a car I've had since August 2015, which I used less than 50% of the time for business.  Each year I  claimed business mileage expenses and multiplied it by the appropriate percentage.   Do I go back 5 or 8 years when I calculate what was deducted for mileage expenses?   I no longer have maintenance records for this vehicle, as they went to the new owner, nor did I depreciate the car, so what would I enter in the box for the basis of gain or loss basis?  I also don't understand what to put in the boxes for Prior Depreciation Equivalent or AMT Prior Depreciation Equivalent?      

[Anonymous_]

@Mike9241 

[christygunther]

I don't see a reply anywhere.  How do I find it?