I will reply since noone else has. It will depend on the category of write off. There are details online, and Google will help. Some cannot be put back on the road. Otherwise yYour insurer might let you keep the car and give you the money. They did that with a colleague, and she then sold the car, which covered the increased cost of her insurance due to loss of NCB. Here is one link:

www.checkthatcar.com/car_writeoff_categories.asp

Note that the car becomes the property of the insurance company, so they can keep it for scrap value. I recently scrapped a 2002 Ford Ka, and I got £150, and collection from my drive way. Hence there is a significant scrap value. The insurance company could offer to sell it to you for the scrap value, or even give it to you.