We have a good friend that had his hail damaged car assessed and the insurance company wanted to flag it as a repairable write off. The car was safe, otherwise sound (no rust or sun perished items) and in good mechanical order. It just looked like a gold ball.
He contacted his insurer (can't remember the company's name) about other options. They indicated that he could cancel the insurance policy, obtain a damage settlement on cancelling and then retain the vehicle for his own use. The vehicle would still be registered as there was nothing which would make it roadworthy. They also advised that he would not be able to get comprehensive insurance on the vehicle possibly by any insurer, including themselves.
The pre-hail damaged vehicle was insured for about $8000 (as it was about a decade old), and the insurance company said it was willing to payout the claim and cancel the policy for about $2000...which gives an implied vehicle value of $6000. He then took the Discovery to a car dealer and asked how much for a trade The dealer said because of the hail damage, it was only worth its scrap value of a few hundred dollars.
He didn't really want to get rid of the Discovery as it has been a good vehicle to him, but based on the above economics, it was not in his financial interests to keep the vehicle. He worried that in a year to two he may have to replace the vehicle and find he would be up for the whole of the cost of the replacement vehicle (less $2000 for the agreed settlement), rather the replacement vehicle cost being $7500 less ($8000 less the excess of $500). He ended up accepting the $7500 for the vehicle being a repairable write off and bought another car.
I suppose if one thinks about another option other than writing the vehicle off and receiving payout for the vehicles value, one must know the risks, especially additional costs which may accrue in the future.