Diminished value is the lost market value a vehicle sustains after an accident — on top of ordinary depreciation — even when repairs restore it to pre-accident condition. A reasonable buyer will not pay the same price for a wrecked-then-repaired vehicle as for one with a clean history, and the accident remains on vehicle history reports (Carfax / AutoCheck).
Three types carriers and courts recognize
Loss from any accident of record after a proper repair — the claim type most firms pursue.
Extra loss when repairs fail to restore appearance or function.
Loss measured before repairs (e.g., trading while still damaged). Less common.