The words you are looking for are "Beyond economical Repair"
Being reasonable if a car costs 17k new and 1 year later is hit head on, the depreciation of the car and the final bill for the repair meet.
So the car could be worth 10k after 12 months, the new parts and labour and spraying plus any hire car charges soon mount up, so its cheaper and easier to pay out the claimant then sell the car and recoup some of the money.
In that scenario, the claimant would only have a hire car for a few day or possibly a week, if it was repaired the car could be away for up to 4 weeks depending on how busy the garage is or parts to arrive, on top of that you have insurance administration man hours to process the claim, its all down to time and wonga
