If a vehicle has been extensively restored or individually modified, it may be advisable to insure it not at its market value or replacement value, but at its restoration value. This refers to the amount that was demonstrably spent to bring the vehicle to its current condition.

In such cases, classic car insurers typically require a detailed appraisal that not only assesses the condition of the vehicle but also documents all verifiable investments in parts and labor. This is usually done by submitting invoices. However, if work was carried out by a private individual, its value can also be accounted for using time sheets or similar records.