What's loose if my sound goes off for a few seconds when I hit a big bump

 

could be anything from remote wire, to power wire, ground, rca connection

 

Are you playing from CDs? It's possible that the CD is actually skipping due to a massive jolt. Not much you can do about that; I suggest steering clear of the craters

If that's not it, does the whole radio turn off? Do any lights go out? It seems like a power or ground connection problem to the radio itself would cause the radio (with lights, etc) to turn off and back on (maybe not even back on!).

 

you would need to tell us what is in the car before we could hazard a guess at what it might be.

Its not a blue car is it? Blue mustangs are bad for stereos........