Yours is curved?
Is it mounted in the back, like a Fender? Or is it directly under the fretboard?
The plastic stuff wrapped around it is to prevent "truss rod buzz". If you happen to have the truss rod completely loose, no pressure, then it can rattle around in there if it's not wrapped in something.
Trust me, that's gotta be one of the most annoying buzzes ever--you play the guitar, you hear buzz, you know it's not coming from the frets or anything else, you know the truss rod is completely loose but the setup is fine as it is, but yet there's this really ANNOYING buzz because the cheap manufacturer didn't wrap the rod.
