If it is suspected that your car is a total loss then the insurer will instruct a valuation to take place.
Whoever the insurer instructs to value your car will be independent and is likely to be the same person /company regardless of who you chose to go with.
If it is going to be written off and you disagree with the valuation then be prepared for a drawn out process with the insurer!
The valuation should take into account not only condition pre accident but also service history etc, even a full tank of petrol might mean £100 don't forget!!!
Don't accept the insurer's first offer!
My dear old Dad had an accident (his fault) a couple of years ago, and wrote off his car. Their first offer was £2500, for a mint, one owner low mileage 5 year old Peugeot old fart mobile. Book value was £4500, private sale. His insurers (Saga) used all sorts of excuses as to why his
car was so lowly valued; "but that's all you'll get trade in " etc. Absolutely disgraceful the way they tried to diddle an old man. I listened in to one negotiation, and they "needed to know before Christmas, your car will be worth a lot less next year"...
I did some research on Autotrader and Ebay, to show them the "asking" prices of similar cars; not easy given the time of year.
Do some research, factor in recent services, new tyres etc, but you will still get shafted. Expect to pay higher premiums as a result for the next 10 years, and make sure the culprit covers not just your excess, but these as well.
Good luck! You're dealing with the biggest tossers in the entire universe!
Edit: It always make me laugh/hit something, when they offer you "legal cover". The not so small print declares that your legal fees are only covered if your insurer deems your case winnable. In which case, shouldn't they be doing the sueing?
Give a man a gun, and he can rob a bank.
Give a man a bank, and he can rob everybody.