Compensation Loss of value in case of accident

Hello, on the weekend a woman drove me on my parked car. Damage according to Mercedes approx. 3800 Euro! Cost assumption of the opposing insurance as well as car rental no problem – so far so good! But one question times: Since I have then forced an accident car (at least a not insignificant pre-damage) the vehicle does not insignificantly lose value! In the private market such cars are very hard to sell…. Can I this value loss compared to the insurance What rules can you follow? What would you recommend to me? Vehicle: Mercedes E280 Built 96, 110TKM Purchase price in Sept. 04 ca. 12,500 Euro…