it wont be a write off mate, had a guy go into the back of mine last year, needed new boot, all the rear prtaically (the pan that hols the spare whatever u call that?) new rear light, spolier, and a back corner re spraying etc.
if you go through your insurance, dont use their authorised repairer - i did a place called just car clinic and they were the worst!
Go to lexus if you goin through insurance, you'll get a top job and a nice courtesey car ;)