yup as far as they are concerned the car is a write off! So if you fix it yourself they will need proof that the work done is good enough, I had to take the car to a reputable pannel beater and get it checked thouraghly to make sure everything was perfect, then I had to goto PG autoglass to get a certificate saying that everything was cool and then I had to re roadworthy the car again. it was a pain in the arse to say the least but I got to keep the car, but I won't lie I did sell the car shortly afterwards, as I wasn't happy with what happened to the car when it was towed away!!
They stole ALLOT of things from my car, they even stripped parts off my engine like the brand new water pump, thermostat housing and viscous fan that I had replaced the week before the accident happened which I personally watched the mechanic fit! they stole my battery, battery cover, center console in the car, my back Leather seats were replaced with some shit that was torn and badly sundamaged, they cut my fuel lines, they stole my engine covers! the list is long. and it cost me in the end to replace all that crap....Never let a tow truck take your car unless they are sent from your insurance company!
Make sure about the cars code status! if you are buying the car back from them I would imagine you would need to re register the car and if its a write off it will definately be a code 3 then you got problems on your hands so just speak to your insurance about that to make sure!