no. there is no loss until he sells it. It's like owning stock.
You are flat out wrong. Not a difference in opinion, just 100% incorrect. The loss has already happened. It is nothing like owning stock, the price will never go back up. It does not hinge on whether or not somebody buys it. The fact that his car is now worth less, and he can't get the full asking price any time he wants to sell it, is the loss.
He could find the closest used car dealer tomorrow and bring it in and take what they offer. The offer would be less than the car is worth due to the accident history. Now he has proven his loss. It makes no difference if he actually sells it or not, if the offer is less than the true value without an accident history, than he has proven his loss.
ANY used car dealer will do a check. Maybe some private buyers will not, but it doesn't matter. He is legally allowed to sell his car to a dealer any time he wants.
You only have 102 posts. You are not one of the 3 most common posters on this site.
I'm not talking about me. Further proof that you are not paying attention.
To the OP, what you're going to have to do is get the car appraised by somebody that specializes in diminished value, and then sue for whatever the loss is. That is the only way you can determine your loss, it has nothing to do with actually selling the car. This is extremely common, ignore all the three idiots fighting here that don't know what they are talking about. Do your own google search on "diminished value". Also there are a lot of very thorough explanations on Youtube for this subject. You likely will not recover the cost of the appraisal, or legal fees, unfortunately that's just the way it is.