Seppuku

So I noticed a while ago that my car apparently has ran over something in the front or hit something at some point before i owned it. Most the peices in the front underneath are misaligned and a little messed up. Theres a plastic peice behind the bumper that comes down and helps hold the under tray to the car its broken and cracked now, the brake ducts line up for **** and pain in the ***, the under tray has some cracks around mounting holes i guess from shifting when it hit, and some mounts may be bent right at the front where the fenders and everything meet. Not sure whats really there. Is the plastic peice i mentioned replacable by itself? I guess one day i should strip it all down and see whats going on.