Sometimes when I hit a speed bump I hear heavy metal jumping. Almost like my car jack and tire iron are moving. But i checked my trunk and everything is sucure. It almost sounds like its coming from underneath the car. What could this be?

 

Loose exhaust system maybe..

 

check the heat plate on top of your cat-converter..mine used to do the same

 

1. rear shocks blowin in the wind? Shockin.... Tires off, lukiluki
2. exhaust pipedo: take and shake. If it drops, off to shoppin driver hops...
3. lower u speed under 100mph