Exhaust was making a squealing noise near catback
 

it would squeal louder as i revved higher, than when i hit a certain rpm it would dissapear than come back when it got to the lower rpms...

i turned off car, restarted it.. still there

i was very worried.. so i drove it around a few blocks. than it dissapeared...

turned off car, turned on car.. no trace of it.

any clues?

Pipes or clamps are loose when cold and after warming up they expand no longer rattle or squeak. Take a look at your exhaust hangers around the gas tank area, they can rub on the metal if the rubber mounts slide back a little.