wrecked and overheatedHey guys my brother wrecked my 04 A4 yesterday, rear ended a g

Hey guys my brother wrecked my 04 A4 yesterday, rear ended a guy. I haven't even seen the thing really don't want too. He drove it from the accident back to his work when he realized the coolant had all leaked out of the radiator and the temp gauge was in the red. He told me once it got in the red he stopped driving it but who knows. What kind of problems can I expect, or look for, as a result of the overheating. I don't mind the front end damage but if I have engine or accesory damage I'm goona be pretty pissed. Thanks for the help.