hmmm, 04 plate car 140 bhp ( is that right ?) at least a couple of grand of damage there, wing and door as you say, looks like pillar also, wing mirror.
I don't know how much your car is worth but my wifes 03 plate mk4 1.6 16v golf with 50k on it is only worth £2k,,,, don't know repair cost but ins estimates are always ridiculous,,, prob come back with a bill for £3.5k or something.
check the value of your car online and send a pic to a repair garage maybe and ask roughly how much if you really want to know, they may give you a rough idea.
also if the ins company come back and say it is to much to repair I think you can possibly ask them for a break down of the est and also what they value your car at, if its close I think you can possibly make them use 2 other companies for a different quote, I also think you can specify a repair garage as they may just use somewhere stupid like vw for their quote which will be ridiculously high.
check it out dude and I hope you paid the £25 extra per annum on your car insurance for guaranteed car hire of which the guy who hit you would be responsible for, well his ins company anyway
hope this helps and good luck