So i left my keys in the open at a party and my car got "joy ridden" and ended up coming back with a smashed up front end. Everythings fixed but the subframe. Anyone have any tips on putting the new one on? (ie. Using new subframe bolts for the same reason as head bolts)

 

you'll probably be fine w/ the old ones. But I'd use new ones to stay on the safe side

 

This is one of the only things I'd have a shop do. I'd take it to a collision repair specialist.