Turbotax is reporting an error that the allowed vehicle depreciation amount (for prior years) is too large. How do I fix this?

[AmeliesUncle]

In many situations, TurboTax can't handle assets that vary in business percentage from year to year.

You would either need to manually figure things out and override (but you can't override using the online software), or use other software that is capable of handing assets that vary in business percentage.