Can file a lost of my car's value in 2018 now?

1. If the car is for personal use, you cannot claim a deduction for a loss on it.

2. You can't claim a loss in value if you still own the car. You claim a loss when you sell something at a loss.

3. Anything that happened in 2018 has to go on your 2018 tax return. You can't claim it in a later year. If you have a deductible loss in 2018 that you did not claim on your 2018 tax return, you could file an amended return for 2018.

4. Prior to 2018 you could claim an itemized deduction for a casualty loss. For example, if the car was damaged in an accident and the full amount of damage was not covered by insurance, you could claim an itemized deduction for the unreimbursed loss, subject to some significant limitations. But the new tax law eliminated that deduction for 2018 through 2025, except for losses caused by a federally declared disaster.