What is “diminished value” and why it matters

“Diminished value” means the loss in a vehicle’s market value caused by an accident, even after repairs restore function and appearance. Buyers often pay less for a car with an accident history. Illinois drivers may seek diminished value compensation from the at‑fault driver’s insurer (or the at‑fault driver directly) as part of a property‑damage claim.

Legal context (Illinois)

Claims for property damage, including diminished value, are generally pursued against the at‑fault party or that party’s insurer. Insurers who adjust claims in Illinois must follow rules and consumer protections in the Illinois insurance framework; for general information about insurance consumer rights in Illinois, see the Illinois Department of Insurance: insurance.illinois.gov. For the text of the Illinois Insurance Code (which governs insurer practices), see the Illinois General Assembly site for the Insurance Code: Illinois Compiled Statutes – Insurance.

Step‑by‑step process to get a solid diminished‑value appraisal

1. Document the post‑accident situation immediately

   Collect repair invoices, all photos (pre‑accident if available and after the crash), the repair facility’s estimate and final invoice, and the vehicle identification number (VIN). Get a vehicle history report (Carfax, AutoCheck). These items form the basis of the appraiser’s analysis.

2. Decide who will prepare the appraisal: independent appraiser vs. dealer vs. insurer

   For a diminished‑value claim you will typically want an independent appraiser with auto valuation experience. Look for appraisers who can produce a written report showing methodology and market comparables. Possible credentials to check: American Society of Appraisers (ASA), International Society of Automotive Appraisers (ISAA) or certification from recognized auto‑appraisal organizations. Avoid relying only on an insurer’s appraiser if you seek third‑party payment from the at‑fault insurer.

3. Hire the appraiser and schedule an inspection

   An appraiser will inspect the vehicle inside and out, review repair records and the vehicle history report, and research market prices for similar, non‑accident vehicles. Typical appraisal costs vary but often range from roughly $200 to $600 depending on complexity.

4. Appraisal methodology and what the report must include

   A credible diminished‑value report should include:

   • Identification: year, make, model, VIN, mileage, trim and options.
   • Pre‑accident market value estimate (using blue book, NADA, past sales, dealer listings).
   • Post‑repair market value estimate (market evidence for similar vehicles with no accident history).
   • Detailed explanation of method used (market comparison, cost approach, or hybrid), plus supporting comparables and sources.
   • Photos of damage and repaired areas, repair invoices, and vehicle history report.
   • Final diminished‑value figure and reasoning.

5. Submit the appraisal to the at‑fault insurer

   Send a dated demand letter that includes the appraisal and repair documents. State that you seek payment of the diminished‑value amount supported by the attached appraisal and give a reasonable deadline for response (commonly 14–30 days). Keep records of delivery (certified mail or email with read receipt).

6. Negotiate or escalate if needed

   The insurer may accept, offer a lower amount, or deny the claim. Typical responses include asking for additional documentation or sending their own appraiser. If negotiations fail, options include filing a demand with the insurer’s consumer complaint office (Illinois Department of Insurance) or filing suit in civil or small claims court.

7. Consider small claims or hiring a lawyer

   If the insurer refuses a reasonable settlement and the amount is within small‑claims limits, you can file in small claims court. For larger or complex claims, consult an attorney experienced in auto property damage and diminished‑value claims. If you decide to sue, the appraisal becomes central evidence to support your damages claim.

Evidence and documentation checklist

• Repair estimates and final repair invoice(s).
• Before/after photos and photos of damage.
• Vehicle history report (Carfax/AutoCheck).
• Comparable listings and dealer quotes for similar vehicles without accident history.
• Appraiser’s written report with methodology, comps, and calculation.
• Purchase documents, maintenance records (if available), and mileage at time of loss.
• Correspondence with insurers (demand letters, emails).

Practical tips and pitfalls

• Do not accept the principle that repair equals full value: reputable appraisals show market evidence that buyers pay less for an accident history.
• Choose an appraiser who will testify in court if necessary; that strengthens the report’s weight.
• Get multiple comparables—one or two dealer listings alone are weak support.
• Keep all original repair invoices and receipts; incomplete records undermine claims.
• Expect insurers to attempt lowball offers—be prepared to explain the appraisal’s market support.
• Track deadlines and preserve proof of service and delivery for any demand letter you send to an insurer.

When to talk to an attorney

If the insurer refuses to negotiate, the at‑fault party denies responsibility, or the diminished value exceeds what you can comfortably handle in small claims court, consult an attorney who handles vehicle property damage. An attorney can explain litigation options, collect further evidence, and calculate recoverable damages (including, when applicable, related out‑of‑pocket costs and interest).