Parts older than 12 Months-No-Sales have less than 5% chance of ever selling again in your dealership. You're better to write them off, and take the loss for tax purposes. That’s why there is a huge push during Year-End at your dealership to write off parts, and get accounting department your numbers. (Note: I say “you’re” better off writing these off – but that’s was the alternative, pre-NADPE days.)