Strange noise and vibration

My partner was driving up a dirt road at about 15-20 ks and she hit a tree root out of the ground it hit the cross member and stooped the car instantly. Now when I start the car it sounds like an exhaust leak I have tightened all the bolts on the exhaust and the extractors as well as all the ones on the intake manifold, but still making strange sounds. I have no idea as to what else it could be and when I looked underneath I could not see anything damaged. Please help.