Insurance will write that off 
I'd agree if it was your own insurance comp paying for the repair.......but its not.....its the other guys....insist it gets repaired at a garage of your choice and they also pay for a hire car for you as well.....ive been there before and trust me you have to put your foot down if the 3rd party insurance comp tries to take the pee
Your entitled to a hire car, like for like.......ok so theres a bit of a problem there as no hire company will have an omega for hire......so just insist its a large saloon car thats auto (if the omega is auto)
Carnt see from the pics.....but is the rear alloy damaged? if so, insist it gets a full alignment check as well.
Last bit of advice......check your insurance policy to see if it has an accident damage company attached to it......if it has.....let them know asap.....they will do all the donkey work for you and make sure you get all your entitled too

How do i know this......i make sure my insurance policies have 'Angel Assist' on them, they're an accident management comp.....costs next to nothing....bout £30 extra/yr......
Good luck
